With the United States still neutral, many Americans simply crossed the border and joined the Royal Canadian Air Force (RCAF) to learn to fly and fight.

Charles Sweeny, a wealthy businessman living in London, persuaded the British Government to form an RAF squadron composed of Americans.

[1] (His uncle, also named Charles Sweeny, had been working along similar lines, recruiting American pilots to fight in France.

[1]) Sweeny's efforts were also coordinated in Canada by the World War I air ace Billy Bishop and the artist Clayton Knight, who formed the Clayton Knight Committee, which by the time the United States entered the war, had processed and approved 6,700 applications from Americans to join the RCAF or RAF.

Sweeny and his rich society contacts bore the cost (over $100,000) of processing and sending the men to the United Kingdom for training.

The basic requirements for joining the Eagle Squadron were a high school diploma, age 20 to 31 years, visual acuity of 20/40 correctable to 20/20, and 300 hours of certified flying time.

71 Squadron, was formed in September 1940 as part of the RAF's buildup during the Battle of Britain,[2] and became operational for defensive duties on 5 February 1941.

The intensity of operations stepped up with a move into No 11 Group of Fighter Command, being based at RAF North Weald by June 1941.

On June 21, 1941, 22 year-old Nathaniel Maranz became the first American pilot to become a prisoner of war when he was shot down by a Bf 109 over the English Channel and picked up by a German patrol boat after swimming for an hour and a half.

The unit soon established a high reputation, and numerous air kill claims were made in RAF fighter sweeps over the continent during the summer and autumn of 1941.

On 26 September 1942, 11 of the unit's 12 brand new Spitfire Mk IXs were lost on a mission over Morlaix while escorting USAAF Boeing B-17 Flying Fortresses in heavy cloud cover.

Strong winds blew the unit further south than realised and, short of fuel, the squadron let down directly over Brest.

One of the British pilots taken prisoner, Flight Lieutenant Gordon Brettell, was later to be shot as one of the escapees in The Great Escape from Stalag Luft III in 1944.

Through to the end of September 1942, the squadrons claimed to have destroyed 73½ German planes while 77 American and 5 British members were killed.

[6] When informed of the attack on Pearl Harbor, most of the Eagle Squadron pilots wanted to immediately join the fight against Imperial Japan.

The pilots from 71 Squadron decided they wanted to go to Singapore to fight the Japanese and a proposal was put to RAF Fighter Command, but it was turned down.

The trio had also all been killed by the time of the transfer of the Eagle Squadrons to the USAAF in 1942 (from the database of the Commonwealth War Graves Commission (CWGC): Phillip Leckrone, service number 84653, was another Battle of Britain veteran.

[14] It is reported that Pilot Officer Art Donahue DFC stayed with the Eagle Squadron only a short time before requesting a transfer back to his original RAF unit.

[15][16] Captain Don Gentile was a pilot with 133 Squadron, claiming two air victories, and by March 1944 had become the 4th Fighter Group's top ace in World War II, with 22 aerial kills.