The U.S. Surveyor General began surveying Kansas after the passage of the Kansas-Nebraska Act of 1854. Plat maps were created at that time to document the surveys. The plats show public lands within the territory divided by range, township and section. Townships were measured in six mile increments starting from the Kansas-Nebraska border. Ranges were numbered in six mile increments east and west from the Sixth Prime Meridian, which crosses through present day Wichita, Kansas. This system is still the basis for legal land description in the state. The Kansas Historical Society acquired a collection of these original plats previously held by the Kansas Secretary of State. The National Archives and the Bureau of Land Management also hold copies of the plats. These two maps show the east and west sides of township 11 south, range 15 east. On the east side, the Kansa "Half Breed" lots are on the north bank of the Kansas River; the west map shows part of the Pottawattomie Reservation, including the Pottawattomie Baptist Mission in the northwest quarter of section 32, which is still standing today on the grounds of the Kansas Historical Society. The town of Indianola, which later became part of North Topeka, is shown on the east portion of the maps.