Final answer:
Daniel Burnham is best known for his role in the City Beautiful movement and his Plan of Chicago, which offered a blueprint for city growth with green spaces, wide boulevards, and suburbs that influenced urban planning throughout the 20th century.
Step-by-step explanation:
Daniel Burnham's greatest contribution to urban design was his pioneering work in developing the City Beautiful movement, which aimed at integrating aesthetics, functionality, and orderly growth into city planning. His Plan of Chicago stands out as a prime example of this approach. Preserving green space, constructing broad boulevards, and aiding in the creation of suburbs were key features of Burnham's urban vision, as illustrated in the blueprint of the Plan of Chicago which became a cornerstone for urban development well into the twentieth century. This approach to city planning was instrumental in combating the challenges of urban sprawl, congestion, and the lack of green spaces in rapidly growing cities.
The movement introduced concepts such as the inclusion of large park areas inside cities, wide boulevards to decrease traffic congestion, and the development of suburbs to reduce city congestion. These core tenets were first showcased at the Columbian Exposition in 1893, where Burnham worked along with Olmsted to design the "White City", laying the groundwork for modern urban planning in America, starting with Washington D.C. in 1901.