Fort Buchanan, was a United States Army post founded in 1856 three miles southwest of present day Sonoita, Arizona in what is now called Hog Canyon. The fort was located on the east slope of the canyon and under constant attack by native Americans. It was officially abandoned in 1861 but during the American Civil War troops of the California Column occasionally manned the post. In February 1865 Apaches attacked and forced the small garrison to retreat. It was then abandoned for good and Fort Crittenden was established half a mile east on the flats in 1867.