Most of the cast were non-professionals, including the two soldiers in the lead roles - Sergeant Donald Prill and Private Walter Newffield. Although the film was distributed in Britain by MGM, it was primarily intended for audiences in America, where it was reportedly shown in 10,000 cinemas. On 26 January 1942, the first American troops stepped ashore at Belfast's Dufferin Quay, and by May the number of Americans had reached 37,000. In 1943 greater numbers arrived in readiness for the Normandy landings, reaching a peak of 120,000 (about one-tenth of the local population) by June 1944. American GI's stationed in Northern Ireland during World War Two became known as 'doughboys'.