What was the first United States aircraft carrier?

On Mar. 20, 1922 the USS Langley (CV 1), converted from the collier* USS Jupiter (AC 3), was placed in commission as the Navy's first aircraft carrier. It was also the US Navy's first turbo-electric-powered ship. Other converted colliers were the USS Lexington (CV 2) commissioned on Dec. 14, 1927 and the USS Saratoga (CV 3) commissioned on Nov. 16, 1927. The USS Ranger (CV 4), the first ship of the U.S. Navy to be designed and constructed as an aircraft carrier, was commissioned 4 Jun. 1934. Langley was named after Samuel Pierpont Langley, an American aviation pioneer. Following another conversion, to a seaplane tender, Langley fought in World War II. On 27 February 1942, she was attacked by nine Japanese bombers and so badly damaged that she had to be scuttled by her escorts.

*A collier is a bulk cargo ship designed to carry coal, especially for naval use by coal-fired warships.