What was the original purpose of the diagonal streets in Chicago?

The original purpose of the diagonal streets in Chicago was to serve as Native American trade routes. Before Chicago was developed into a major urban center, the area was inhabited by various Indigenous tribes who established trade networks. These diagonal streets followed the natural landforms and paths that the Native Americans used, making them practical for travel and trade between different locations.

The later development of these routes into the city’s street system reflects a recognition of the historical significance and functional advantages of these pathways, which facilitated movement and interaction. This foundational aspect contributed to shaping the urban layout of Chicago as it grew in the 19th century, ultimately influencing the city's growth and design.