Military installations along the route of the Overland Mail Company, from east to west, during the period in which the route was being run:
- Fort Smith, Arkansas – 1817-1871
- Fort Washita, near Colbert’s Ferry, Indian Territory – 1843-1858
- Fort Belknap, Texas – 1851-1859
- Camp Cooper, Texas, near Fort Griffin – 1856-1861
- Fort Phantom Hill, Texas – 1851-1854
- Fort Chadbourne, Texas – 1852-1867
- Fort McKavett, Texas, below head of Concho – 1852-1867
- Fort Lancaster, Texas – 1855-1861
- Fort Stockton, Texas – 1859-1861
- Fort Davis, Texas – 1854-1861
- Fort Quitman, Texas – 1858-1861
- Fort Bliss, Texas – 1849-present
- Fort Filmore, New Mexico – 1851-1862
- Fort Thorn, New Mexico – 1853-1859
- Fort MacLane, New Mexico, near Mimbres River – 1860-1865
- Fort Buchanan, Arizona – 1856-1861
- Fort Yuma, California – 1850-1883
- Fort Gaston, California, 30 miles north of Fort Yuma – 1859-1864
- Fort Tejon, California – 1854-1864