The 1947 All-Ireland SFC final was the only decider ever played outside of Ireland. Cavan and Kerry qualified for the final which was played at the Polo Grounds, New York. The main driving force behind the GAA Central Council decision to give the US Gaels this honour was Canon Hamilton of Clare. He was a powerful man both in physique and character. His courage and strength of character were never more dramatically demonstrated than on the occasion of the first entry of the newly-formed Irish National Army into Ennis at the height of the Civil War, which had tragically divided the people of Clare. His presence in the front seat of an open lorry, at the head of the Army convoy, gave an imprimatur to the event which was not challenged. He gave a lifetime of service to the promotion of Gaelic Games, the Irish language and music. He died as he had lived while attending a County Hurling Final in Cusack Park, Ennis.
The final at the Polo Grounds drew an attendance of 34,941 and was played in intense heat. Kerry matched the weather with a blistering start. A point by Gega O'Connor early on was soon followed by a brilliant solo goal from Batt Garvey, and fifteen minutes after the throw-in, the Munster champions were eight points in front. But then, the Northern captain and centre-half back, John Joe O'Reilly really stormed on the scene. He inspired and prompted his team in magnificent style as Cavan went resolutely about improving the depressing position. And with strong support from Mick Higgins, who led the attack superbly, and the accurate Peter O'Donoghue, who hit eight immaculate points, Cavan battled back to achieve probably the county's greatest ever win: 2-11 to 2-7. The Cavan captain, John Joe O'Reilly, led his county to success again the following season at Croke Park against Mayo. The Army man, who with his brother 'Big Tom' had first worn the Cavan colours in 1937, was a born leader of men. He died in November 1952 and is remembered in the ballad "Lament for John Joe O'Reilly".