Fort Whipple was a United States (U.S.) Army post temporarily established at Del Rio Springs, north of present day Chino Valley, Arizona, by Major Edward Banker Willis and Captain Nathaniel J. Pishon on December 23, 1863. They led Companies C and F of the First California Volunteers and built the post under General Order #27 issued by General James Henry Carleton. The post was named Fort Whipple, after Amiel Weeks Whipple, an American military officer and topographical engineer. He served as a brigadier general in the American Civil War, and was mortally wounded on May 7, 1863 at the Battle of Chancellorsville in Virginia.