The Northwest Ordinance of 1787 and the Land Ordinance of 1785 were designed to establish some order among western settlers. The Land Ordinance prescribed the division of the land into six-mile-square townships. By 1820, townships had been laid out in the southern part of Illinois, and a solid band of them (the Bounty Lands) lined the northwest side of the Illinois River, working up toward the site of Chicago.

Meanwhile, the United Tribes had in 1816 agreed to cede to the federal government a corridor of land stretching southwestward from Chicago; between these Indian Boundary Lines a canal was to be built. During the early 1820s, townships were laid out in this corridor, to link up with the Bounty Lands. By 1830, the site of Chicago itself had been surveyed, as the eastern terminus of the canal corridor, and during the 1830s further surveys covered the whole of the future metropolitan area, west to the Fox River and north to the Wisconsin border. In 1827, the federal government had assigned to the canal commissioners 286,000 acres within the canal corridor. From their headquarters in Lockport, the commissioners then sold this land, so that between 1836 and 1848 they were able to construct the Illinois & Michigan Canal, the basis for Chicago's emergence. As the city grew, its streets tended to develop on the section lines platted in 1830, so that the early surveyors in effect determined much of the outline of the modern grid. Indeed, the streets followed the grid so faithfully that in time the effect became wearisome, and in new suburbs like Riverside (platted in 1869) there was a determined attempt to set the streets out in more “natural,” flowing lines.

With the adjacent metropolitan area now covered by the township-and-range grid, the surveyors' townships in many cases became civil townships, with names like Hanover, Lemont, and York, which survive to the present day. The townships for some years also had important administrative functions, but these withered over time, until today they are chiefly known for their role as school districts. As time went by, municipal entities emerged that overlapped the townships, more and more blurring their outlines. But these offspring of the Land Ordinance of 1785 had played an important role in early settlement, and continued in many cases as the origin of modern roads.

David Buisseret