Fort Simple was an American fort built in Topeka, Kansas, as a result of Maj. Gen. Sterling Price's Missouri Raid in the late summer and fall of 1864. Topeka had become the permanent capital of the State of Kansas in 1861, but no fortifications had been built to protect the city from guerrilla bands, which roamed eastern Kansas. Even the raid and massacre in August 1863 in Lawrence, Kansas, did not result in a fort being built to protect the capital, although plans had been made to build one by July 1864.