Under a contract with the U.S. Army, Colt Arms built the Model 1895 ten-barrel variant of the Gatling Gun, capable of firing 800–900 .30 Army rounds per minute, and used with great effect at the Battle of San Juan Hill. The M1895 Colt–Browning machine gun or "Potato Digger" was built by Colt. The Colt–Browning was one of the first gas-operated machine guns, originally invented by John Browning. It became the first automatic machine gun adopted by the United States and saw limited use by the U.S. Marine Corps at the invasion of Guantánamo Bay and by the 1st Volunteer Infantry in the Santiago campaign during the Spanish–American War. In 1901, Elizabeth Jarvis Colt sold the company to a group of outside investors based in New York and Boston.