The downtown core of Buffalo began to emerge as a commercial district in the late nineteenth century, when the introduction of a network of streetcars and the development of structural steel led to the decentralization of the city's population. The Labor Day crowd in this photo displays the busy economic district on Main Street around the turn of the twentieth century.

Once a residential district, Main Street became the hub of the region's economic activity as the intricate transportation network of streetcars enabled the city's population to spread out into distinct residential neighborhoods within the heart of the city. The 25 streetcars running by the turn of the century connected all these neighborhoods, along nearly 90 miles of track, to the emerging central core of economic activity on Main Street.

The development of structural steel in the building industry allowed for the construction of buildings – such as the Guaranty and the Ellicott Square buildings – that grew upward in an effort to more efficiently serve the growing population.