What year did Alfred Hitchcock become a citizen of the United States?

Sir Alfred Joseph Hitchcock (13 August 1899 – 29 April 1980) was an English film director and producer, at times referred to as "The Master of Suspense". He pioneered many elements of the suspense and psychological thriller genres. He had a successful career in British cinema with both silent films and early talkies and became renowned as England's best director. Hitchcock moved to Hollywood in 1939, and became a U.S. citizen in 1955.

Prior to 1980, there had long been talk of Hitchcock being knighted for his contribution to film. Critic Roger Ebert wrote: "Other British directors like Sir Carol Reed and Sir Charlie Chaplin were knighted years ago, while Hitchcock, universally considered by film students to be one of the greatest filmmakers of all time, was passed over". Hitchcock later received his knighthood from Queen Elizabeth II in the 1980 New Year Honours.

During the First World War, Hitchcock was called up to serve in the British Army; he was ultimately excused from military service with a 'C3' classification due to his size, height or an unnamed medical condition, but was nonetheless "able to stand service conditions in garrisons at home". Hitchcock joined a cadet regiment of the Royal Engineers in 1917. His military stint was limited, and he mainly engaged in theoretical briefings, weekend drills, and exercises. Hitchcock would march around London's Hyde Park and was required to wear puttees, though he never mastered the proper wrapping of them.