Oklahoma County, Oklahoma: History
The area that would someday be called Oklahoma County was originally inhabited by members of the indigenous nations of the Southern Plains, but by the 1830s the land would become part of the territory assigned to the Seminoles and Creeks after their removal from their ancestral lands in the Southeastern USA.
As a result of the Reconstruction era treaties signed between the US government and the Seminole and Creek nations in 1866, the land was taken from tribal jurisdiction but not assigned to other tribal governments, which in time led it to be called the Unassigned Lands. In 1889, the US federal government held a land run for the Unassigned lands, which led to the rapid settlement of the area.
By 1890, Oklahoma County was called "County Two" and was one of seven counties established by the Organic Act of 1890.
County business initially took place in a building at the intersection of California Avenue and Robinson Street until the construction of the first Oklahoma County Courthouse at 520 West Main Street in the 1900s. In 1937, the county government was moved to a building at 321 Park Avenue, which now serves only as the county courthouse.