Burnham and Root had accepted responsibility to oversee design and construction of the World's Columbian Exposition in Chicago’s then desolate Jackson Park on the south lakefront. The largest world's fair to that date (1893), it celebrated the 400-year anniversary of Christopher Columbus' famous voyage. After Root's sudden and unexpected death, a team of distinguished American architects and landscape architects, including Burnham, Frederick Law Olmsted, Charles McKim and Louis Sullivan, radically changed Root's modern and colorful style to a Classical Revival style. Under Burnham's direction, the construction of the Fair overcame huge financial and logistical hurdles, including a worldwide financial panic and an extremely tight timeframe, to open on time. Considered the first example of a comprehensive planning document in the nation, the fairground was complete with grand boulevards, classical building facades, and lush gardens. Often called the "White City", it popularized neoclassical architecture in a monumental and rational Beaux-Arts plan. The remaining population of architects in the U.S. were soon asked by clients to incorporate similar elements into their designs.

Initiated in 1906 and published in 1909, Burnham and his co-author Edward H. Bennett prepared "The Plan of Chicago", which laid out plans for the future of the city. It was the first comprehensive plan for the controlled growth of an American city, and an outgrowth of the City Beautiful movement. The plan included ambitious proposals for the lakefront and river and declared that every citizen should be within walking distance of a park. Sponsored by the Commercial Club of Chicago, Burnham donated his services in hopes of furthering his own cause. Plans and conceptual designs of the south lakefront from the Exposition came in handy, as he envisioned Chicago being a "Paris on the Prairie". French inspired public works constructions, fountains, and boulevards radiating from a central, domed municipal palace became Chicago's new backdrop. Though only parts of the plan were actually implemented, it set the standard for urban design, anticipating future need to control unexpected urban growth, and continued to influence the development of Chicago long after Burnham's death.

City planning projects did not stop at Chicago though. Burnham contributed to plans for cities such as Cleveland (the Group Plan), San Francisco, and Manila and Baguio in the Philippines, details of which appear in "The Chicago Plan" publication of 1909. His plans for the redesign of San Francisco were delivered to City Hall on April 17, 1906, the day before the 1906 earthquake. In the haste to rebuild the city, the plans were ultimately ignored. The Plan for Manila was not fulfilled, except for a shore road, which became Dewey boulevard, now known as Roxas boulevard.

In Washington, DC, Burnham did much to shape the McMillan Plan, which led to the completion of the overall design of the National Mall. Going well beyond Pierre L'Enfant's original vision for the city, the plan provided for the extension of the Mall beyond the Washington Monument to a new Lincoln Memorial and a "pantheon" that eventually materialized as the Jefferson Memorial. Inter alia, this involved significant reclamation of land from swamp and the Potomac River, and the relocation of an existing railroad station on the site, which was replaced by Burnham's own design for Union Station.

Much of his career work modeled the classical style of Greece and Rome. In his 1924 autobiography, Louis Sullivan, considered by many to be the greatest architect from the Chicago School, chastised the late Burnham for his lack of original expression and dependence on Classicism. Sullivan went on to claim that "the damage wrought by the World's Fair will last for half a century from its date, if not longer" — a sentiment edged with bitterness, as corporate America of the early twentieth century had demonstrated a strong preference for Burnham's architectural style over Sullivan's.

Burnham was quoted after his death as saying, "Make no little plans. They have no magic to stir men's blood and probably will not themselves be realized." (Moore 1921) This slogan has been taken to capture the essence of Burnham's spirit, although there is no documented evidence that he actually used those words.

A man of influence, Burnham was considered the preeminent architect in America at the turn of the twentieth century. He held many positions during his lifetime, including the presidency of the American Institute of Architects. Other notable architects began their careers under his aegis, such as Joseph W. McCarthy. In 1912, when he died in Heidelberg, Germany, D.H. Burnham and Co. was the world's largest architectural firm. Legendary architect Frank Lloyd Wright eulogized, "(Burnham) made masterful use of the methods and men of his time... (as) an enthusiastic promoter of great construction enterprises... his powerful personality was supreme." His firm continues its work today under the name Graham, Anderson, Probst & White, which it adopted in 1917.

Almost as a tribute to his urban planning ethos, Burnham's final resting spot is given special attention, being located on the only island in the park-like Graceland Cemetery, situated in Chicago's Lakeview neighborhood. Because he was the planner and architect of Baguio City in the Philippines, the city's Burnham Park was named after him. In his honor, the American Planning Association named a major annual prize the Daniel Burnham Award for a Comprehensive Plan. An alley in San Francisco, formerly Hemlock Street between Van Ness Avenue and Franklin Street, was renamed in Burnham's honor.

Collections of Burnham's personal and professional papers, photographs, and other archival materials are held by the Ryerson and Burnham Archives at the Art Institute of Chicago.

The Daniel Burnham Memorial Competition (Chicago) was held in 2009 to create a memorial to Daniel Burnham and his Plan of Chicago. Daniel Burnham Court, a building, is also named after him as is the street, Daniel Burnham Court.