Thompson's Plat - 1830[source]

The Illinois and Michigan Canal Commissioners hired James Thompson, a surveyor from Kaskaskia in downstate Randolph County, to create Chicago's first plat (or map showing proposed lots) in 1830. He laid out the town with straight streets uniformly 66 feet wide (the length of a surveyor's chain) with alleys 16 feet wide bisecting each block

Known Streets