Department of the Interior (General Land Office)
The Wisconsin public land surveys were nearly completed when this map was made. At the time, the first government land offices established in Wisconsin at Green Bay, Milwaukee and Mineral Point had already closed down, since most of the available land nearby had been bought or given away. Land sales were still going strong, however, in central, western and northern Wisconsin.
To encourage the development of railroads, the U.S. government granted the state of Wisconsin 3.65 million acres. These lands lay in an alternating, or checkerboard, section pattern on each side of the right-of-way. They were sold to help finance railroad construction. The grants to Wisconsin were part of 131 million acres granted by the federal government for railroad construction in states included in the Public Land Survey System.
The border between Wisconsin and Illinois was the east-west baseline used for systematic land surveys in Wisconsin. The north-south anchor line was the fourth Principal Meridian. As noted on the map, correction lines were established every tenth tier of townships because of the convergence of meridian lines as they approach the North Pole.