Morse's Calvinist beliefs are evident in his painting the Landing of the Pilgrims, through the depiction of simple clothing as well as the austere facial features. This image captured the psychology of the Federalists; Calvinists from England brought to the United States ideas of religion and government thus forever linking the two countries. More importantly, this particular work attracted the attention of the famous artist, Washington Allston. Allston wanted Morse to accompany him to England to meet the artist Benjamin West. An agreement for a three-year stay was made with Jedidiah, and young Morse set sail with Allston aboard the Lydia on July 15, 1811.

Upon his arrival in England, Morse diligently worked to perfect painting techniques under Allston's watchful eye; by the end of 1811, he gained admittance to the Royal Academy. At the Academy, he fell in love with the Neo-classical art of the Renaissance and paid close attention to Michelangelo and Raphael. After observing and practicing life drawing and absorbing its anatomical demands, the young artist successfully produced his masterpiece, the Dying Hercules.

To some, the Dying Hercules seemed to represent a political statement against the British and also the American Federalists. The muscles apparently symbolized the strength of the young and vibrant United States versus the British and British-American supporters. During Morse’s time in Britain the Americans and British were engaged in the War of 1812 and division existed within United States society over loyalties. Anti-Federalist Americans aligned themselves with the French, abhorred the British, and believed a strong central government to be inherently dangerous to democracy. As the war raged on, his letters to his parents became more anti-Federalist in tone. In one such letter Morse said, "I assert that the Federalists in the Northern States have done more injury to their country by their violent opposition measures than a French alliance could. Their proceedings are copied into the English papers, read before Parliament, and circulated through their country, and what do they say of them... they call them (Federalists) cowards, a base set, say they are traitors to their country and ought to be hanged like traitors."

Although Jedidiah did not change his political views, he did influence Morse’s in another way. It is unmistakably clear that Jedidiah’s Calvinist ideas were an integral part of Morse’s other significant English piece Judgment of Jupiter. Jupiter in the cloud, accompanied by his eagle, with his hand over the parties, is pronouncing judgment. Marpessa with an expression of compunction and shame, imploring forgiveness, is throwing herself into the arms of her husband. Idas, who tenderly loved Marpessa, is eagerly rushing forward to receive her, while Apollo stares with surprise… at the unexpectedness of her decision...

A case can be made that Jupiter is representative of God’s omnipotence watching every move that is made. One might deem the portrait as a moral teaching by Morse on infidelity. Although Marpessa fell victim she realized that her eternal salvation was important and desisted from her wicked ways. Apollo shows no remorse for what he did, but just stands there with a puzzled look. A lot of the American paintings throughout the early nineteenth century had religious themes and tones and it was Morse who was the forerunner. Judgment of Jupiter allowed Mr. Morse to express his support of Anti Federalism while maintaining his strong spiritual convictions. This work represented American nationalism through Calvinism because these individuals expelled from England, contributed to the expulsion of the British (1776 and now in 1812) and established a free democratic society. West sought to present this image at another Royal Academy exhibition; unfortunately his time had run out. He left England on August 21, 1815 and began his full-time career as an American painter.

The years 1815 – 1825 marked significant growth in Morse’s paintings as he sought to capture the essence of America’s culture and life. He had the honor of painting former Federalist President John Adams (1816). He hoped to become part of grander projects and saw his opportunity with the clash between Federalist and Anti-Federalists over Dartmouth College. Morse was able to paint Judge Woodward (1817) who was involved in bringing the Dartmouth case before the U.S. Supreme Court and the college’s president, Francis Brown. He sought commissions in Charleston, South Carolina (1818). Morse’s painting of Mrs. Emma Quash symbolized the opulence of Charleston. It seemed for the time being, the young artist was doing well for himself.

Between 1819 and 1821, Morse experienced a great change in his life. Nothing stayed the same after that. Commissions ceased in Charleston when the city was hit with an economic recession related to the Panic of 1819. Jedidiah was forced to resign from his ministerial position as he was unsuccessful in stopping the rift within Calvinism. The new branch that formed was the Congregational Unitarians which he deemed as detestable anti-Federalists because these persons took a different approach over salvation. Although he respected his father’s religious opinions, he sympathized with the Unitarians. A prominent family that converted to the new Calvinist faith was the Pickerings of Portsmouth whom Morse had painted. This portrait can then be viewed as a further shift towards anti-Federalism. A person could argue that he made his full transition to anti-Federalism when he was commissioned to paint President James Monroe (1820). Monroe embodied Jeffersonian Democracy by favoring the common man over the aristocrat; later reemphasized upon the ascension of Andrew Jackson.

There were two defining commissions that shaped Morse’s art career from his return to New Haven until the establishment of the National Academy of Design. The Hall of Congress (1821) and the Marquis de Lafayette (1825) engaged Morse’s sense of democratic nationalism. The Hall of Congress was designed to capitalize on the astonishing success of François-Marius Granet's The Capuchin Chapel in Rome which toured the United States extensively throughout the 1820s, attracting audiences willing to pay the 25-cent admission fee. The artist chose to paint the House of Representatives, in a similar way, with careful attention to architecture and dramatic lighting. He also wished to select a uniquely American topic that would bring glory to the young nation, and his topic did just that, showing American democracy in action. He traveled to Washington D.C. to draw the architecture of the new halls, carefully placing eighty individuals within the painting and believed that a night scene was appropriate. He successfully balanced the architecture of the Rotunda with the figurines and the glow of the lamplight serving as the focal point of the work. Pairs of people, those who stood alone, individuals bent over their desks working were painted simply but had characterized faces. Morse chose nighttime to convey Congress’ dedication to the principles of democracy transcended day. The Hall of Congress however, failed to draw a crowd in New York City. One possible reason for the disappointment was the shadow of John Trumbull’s Declaration of Independence that won popular acclaim in 1820. A second explanation is that the overwhelming attention to the architecture of the Hall of Congress overshadows the individuals, making it hard to appreciate the drama of what was actually happening.

Morse felt a great degree of honor of painting the Marquis de Lafayette, leading supporter of the American Revolution. He felt compelled to paint a grandiose portrait of the man who helped to establish a free and independent America. In his image, he enshrouds Lafayette with a magnificent sunset as he stands to the right of three pedestals of which two are Benjamin Franklin and George Washington with the final reserved for him. A peaceful wooden landscape below him symbolized American tranquility and prosperity as it approach the age of fifty. The developing friendship between Morse and Lafayette and the discussion of the Revolutionary War, affected the artist upon returning to New York City.

Morse was in Europe for three years improving his painting skills, 1830 – 1832, travelling in Italy, Switzerland and France. The project he eventually selected was to paint miniature copies of some 38 of the Louvre's famous paintings on a single canvas (6 ft. x 9 ft) which he entitled The Gallery of the Louvre, planning to complete the work upon his return to the United States. On a subsequent visit to Paris in 1839, Morse met Louis Daguerre and became interested in the latter's daguerreotype, the first practical means of photography. Morse wrote a letter to the New-York Observer describing the invention, which was published widely in the American press and provided a broad awareness.

In 1825, the city of New York commissioned Morse for $1,000 to paint a portrait of Gilbert du Motier, marquis de Lafayette, in Washington. In the midst of painting, a horse messenger delivered a letter from his father that read one line, "Your dear wife is convalescent". Morse immediately left Washington for his home at New Haven, leaving the portrait of Lafayette unfinished. By the time he arrived she had already been buried. Heartbroken in the knowledge that for days he was unaware of his wife's failing health and her lonely death, he moved on from painting to pursue a means of rapid long distance communication.

On the sea voyage home in 1832, Morse encountered Charles Thomas Jackson of Boston who was well schooled in electromagnetism. Witnessing various experiments with Jackson's electromagnet, Morse developed the concept of a single-wire telegraph, and The Gallery of the Louvre was set aside. The original Morse telegraph, submitted with his patent application, is part of the collections of the National Museum of American History at the Smithsonian Institution. In time the Morse code would become the primary language of telegraphy in the world, and is still the standard for rhythmic transmission of data.

William Cooke and Professor Charles Wheatstone learned of the Wilhelm Weber and Carl Gauß electromagnetic telegraph in 1833, and reached the stage of launching a commercial telegraph prior to Morse, despite starting later. In England, Cooke became fascinated by electrical telegraph in 1836, four years after Morse, but with greater financial resources. Cooke abandoned his primary subject of anatomy and built a small electrical telegraph within three weeks. Wheatstone also was experimenting with telegraphy and (most importantly) understood that a single large battery would not carry a telegraphic signal over long distances, and that numerous small batteries were far more successful and efficient in this task (Wheatstone was building on the primary research of Joseph Henry, an American physicist). Cooke and Wheatstone formed a partnership and patented the electrical telegraph in May 1837, and within a short time had provided the Great Western Railway with a 13-mile (21 km) stretch of telegraph. However, Cooke and Wheatstone's multiple wire signaling method would be overtaken by Morse's superior method within a few years.

In a letter to a friend, Morse describes how vigorously he fought for being called the sole inventor of the electromagnetic telegraph despite the previous inventions (1848).

I have been so constantly under the necessity of watching the movements of the most unprincipled set of pirates I have ever known, that all my time has been occupied in defense, in putting evidence into something like legal shape that I am the inventor of the Electro-Magnetic Telegraph!! Would you have believed it ten years ago that a question could be raised on that subject?

Morse encountered the problem of getting a telegraphic signal to carry over more than a few hundred yards of wire. His breakthrough came from the insights of Professor Leonard Gale, who taught chemistry at New York University (a personal friend of Joseph Henry). With Gale's help, Morse soon was able to send a message through ten miles (16 km) of wire. This was the great breakthrough Morse had been seeking. Morse and Gale were soon joined by a young enthusiastic man, Alfred Vail, who had excellent skills, insights and money. Morse's telegraph now began to be developed very rapidly.

In 1838 a trip to Washington, D.C., failed to attract federal sponsorship for a telegraph line. Morse then traveled to Europe seeking both sponsorship and patents, but in London discovered Cooke and Wheatstone had already established priority. Morse would need the financial backing of Maine congressman Francis Ormand Jonathan Smith.

Morse made one last trip to Washington, D.C., in December 1842, stringing "wires between two committee rooms in the Capitol, and sent messages back and forth" to demonstrate his telegraph system. Congress appropriated $30,000 in 1843 for construction of an experimental 38-mile (61 km) telegraph line between Washington, D.C., and Baltimore, Maryland, along the right-of-way of the Baltimore and Ohio Railroad. An impressive demonstration occurred on May 1, 1844, when news of the Whig Party's nomination of Henry Clay for U.S. President was telegraphed from the party's convention in Baltimore to the Capitol Building in Washington. On May 24, 1844, the line was officially opened as Morse sent the famous words "What hath God wrought" from the B&O's Mount Clare Station in Baltimore to the Capitol Building along the wire. Annie Ellsworth chose these words from the Bible (Numbers 23:23); her father, U.S. Patent Commissioner Henry Leavitt Ellsworth, had championed Morse's invention and secured early funding for it.

In May 1845 the Magnetic Telegraph Company was formed in order to radiate telegraph lines from New York City towards Philadelphia, Boston, Buffalo, New York and the Mississippi.

Morse also at one time adopted Wheatstone and Carl August von Steinheil's idea of broadcasting an electrical telegraph signal through a body of water or down steel railroad tracks or anything conductive. He went to great lengths to win a law suit for the right to be called "inventor of the telegraph", and promoted himself as being an inventor, but Alfred Vail played an important role in the invention of the Morse Code, which was based on earlier codes for the electromagnetic telegraph.

Samuel Morse received a patent for the telegraph in 1847, at the old Beylerbeyi Palace (the present Beylerbeyi Palace was built in 1861 – 1865 on the same location) in Istanbul, which was issued by Sultan Abdülmecid who personally tested the new invention.

In the 1850s, Morse went to Copenhagen and visited the Thorvaldsens Museum, where the sculptor's grave is in the inner courtyard. He was received by King Frederick VII, who decorated him with the Order of the Dannebrog. Morse expressed his wish to donate his portrait from 1830 to the king. The Thorvaldsen portrait today belongs to Margaret II of Denmark.

The Morse telegraphic apparatus was officially adopted as the standard for European telegraphy in 1851. Only the United Kingdom (with its extensive overseas British Empire) kept the needle telegraph of Cooke and Wheatstone.

There is an argument amongst historians that Morse may have received the idea of a plausible telegraph from Harrison Gray Dyar some eighteen years earlier than his patent.

According to his The New York Times obituary published on April 3, 1872, Morse received respectively the decoration of the Atiq Nishan-i-Iftikhar (English: Order of Glory), set in diamonds, from the Sultan Ahmad I ibn Mustafa of Turkey (c.1847), a golden snuff box containing the Prussian gold medal for scientific merit from the King of Prussia (1851); the Great Gold Medal of Arts and Sciences from the King of Württemberg (1852); and the Great Golden Medal of Science and Arts from Emperor of Austria (1855); a cross of Chevalier in the Légion d'honneur from the Emperor of France; the Cross of a Knight of the Order of the Dannebrog from the King of Denmark (1856); the Cross of Knight Commander of the Order of Isabella the Catholic, from the Queen of Spain, besides being elected member of innumerable scientific and art societies in the United States and other countries. Other awards include Order of the Tower and Sword from the kingdom of Portugal (1860); and Italy conferred on him the insignia of chevalier of the Order of Saints Maurice and Lazarus in 1864.

In the United States, Morse had his telegraph patent for many years, but it was both ignored and contested. In 1853 the case of the patent came before the U.S. Supreme Court where, after very lengthy investigation, Chief Justice Roger B. Taney ruled that Morse had been the first to combine the battery, electromagnetism, the electromagnet and the correct battery configuration into a workable practical telegraph. Nevertheless, in spite of this clear ruling, Morse still received no official recognition from the United States government.

Assisted by the American ambassador in Paris, the governments of Europe were approached regarding how they had long neglected Morse while using his invention. There was then a widespread recognition that something must be done, and "in 1858 Morse was awarded the sum of 400,000 French francs (equivalent to about $80,000 at the time) by the governments of France, Austria, Belgium, the Netherlands, Piedmont, Russia, Sweden, Tuscany and Turkey, each of which contributed a share according to the number of Morse instruments in use in each country." In 1858, he was also elected a foreign member of the Royal Swedish Academy of Sciences.

There was still no such recognition in the U.S. This remained the case until June 10, 1871, when a bronze statue of Samuel Morse was unveiled in Central Park, New York City. An engraved portrait of Morse appeared on the reverse side of the United States two-dollar bill silver certificate series of 1896. He was depicted along with Robert Fulton. An example can be seen on the website of the Federal Reserve Bank of San Francisco's website in their "American Currency Exhibit".

A blue plaque was erected to commemorate him at 141 Cleveland Street, London, where he lived from 1812 to 1815.

In addition to the telegraph, Morse invented a marble-cutting machine that could carve three dimensional sculptures in marble or stone. Morse couldn't patent it, however, because of an existing 1820 Thomas Blanchard design.

In the 1850s, Morse became well known as a defender of America's institution of slavery, considering it to be sanctioned. In his treatise "An Argument on the Ethical Position of Slavery," he wrote:

My creed on the subject of slavery is short. Slavery per se is not sin. It is a social condition ordained from the beginning of the world for the wisest purposes, benevolent and disciplinary, by Divine Wisdom. The mere holding of slaves, therefore, is a condition having per se nothing of moral character in it, any more than the being a parent, or employer, or ruler.

Samuel Morse was a generous man who gave large sums to charity. He also became interested in the relationship of science and religion and provided the funds to establish a lectureship on 'the relation of the Bible to the Sciences'. Morse was not a selfish man. Other people and corporations made millions using his inventions, yet most rarely paid him for the use of his patented telegraph. He was not bitter about this, though he would have appreciated more rewards for his labors. Morse was comfortable; by the time of his death, his estate was valued at some $500,000.

Morse died on April 2, 1872, 25 days short of his 81st birthday. He died of pneumonia. He was at his home at 5 West 22nd Street, New York City, at the age of 80, and was buried in the Green-Wood Cemetery in Brooklyn, New York.

Morse was a leader in the anti-Catholic and anti-immigration movement of the mid-19th century. In 1836, he ran unsuccessfully for mayor of New York under the anti-immigrant Nativist Party's banner, receiving only 1496 votes. When Morse visited Rome, he refused to take his hat off in the presence of the Pope. Upon seeing this, an offended Swiss Guardsman rushed over and hit the hat off of his head. Morse worked to unite Protestants against Catholic institutions (including schools), wanted to forbid Catholics from holding public office, and promoted changing immigration laws to limit immigration from Catholic countries. On this topic, he wrote, “We must first stop the leak in the ship through which muddy waters from without threaten to sink us.” Morse was the author of a number of letters to the New York Observer (his brother Sidney was the editor at the time) urging people to fight the perceived Catholic menace. These articles were widely reprinted in other newspapers. Among other claims, he believed that the Austrian government and Catholic aid organizations were subsidizing Catholic immigration to the United States in order to gain control of the country.

In his Conspiracy Against the Liberties of the United States, Morse wrote: “Surely American Protestants, freemen, have discernment enough to discover beneath them the cloven foot of this subtle foreign heresy. They will see that Popery is now, what it has ever been, a system of the darkest political intrigue and despotism, cloaking itself to avoid attack under the sacred name of religion. They will be deeply impressed with the truth, that Popery is a political as well as a religious system; that in this respect it differs totally from all other sects, from all other forms of religion in the country.”