This is one of many such sales of public lands to fund railroad construction. As is explained in this advertising booklet, the Federal Congress granted the State of Illinois 2.5 million acres of public lands to aid construction of a rail line in Illinois. The State legislature created the Illinois Central Railroad Company and in turn granted it the land. The route would run from the Northwest corner of Illinois to Cairo in the south, with a branch to Chicago. The lands that were granted were in the vicinity of the rail lines. The railroads were to sell most of the land (except land that would be used for the lines) and use the cash they received from sales for construction. This advertising booklet seems mainly aimed at farmers or prospective farmers who might be interested in purchasing land, and provides over 60 pages of information for them.