George Henry was educated at Oscott (a Catholic school in England) and at Cambridge. He also studied law in London for a short time but his interest was mainly in horses. In 1835 the Church at Carnacon was built at a cost £2,000. Moore contributed substantially to the cost. A painting of Crucifixion by James Browne was hung over altar (Painting missing after reconstruction). His brother Arthur Augustus was killed while riding Mickey Free in the 1845 Grand National. The grief stricken George Henry withdrew and shut himself in Moore Hall House, reflecting on the catastrophe of his brothers death and the plight of his hungry tenants.
He conceived the idea of entering his horse Coranna for the Chester Cup and placing bets on him to win. With Frank Butler in the saddle Coranna won the Chester Cup on 6th May 1846. A portrait of Coranna still hangs in the church in Carnacon. The prize money and George Henry's backing exploit netted £17,000. Back again in Ireland he set about aiding his tenants in their plight. With the help of the Marquess of Sligo and Robert Blosse the ship "Martha Washington" was chartered. The ship arrived in Westport July 1847 with 4,000 tons of maize. The population on Moores estate was secured by his compassion. A cow was also given to each tenant family. It is still remembered that no one died on the Moore estate during the famine and no evictions were ever recorded. In 1846 George Henry stood for election in Mayo but was defeated. The following year he was elected M.P. for Mayo and headed the poll. He began his political career by pressing the English Government for immediate relief for the starving population of Ireland. He was returned for Mayo again in 1852. Irish Members numbered 50 after election and they brought about the defeat of the Tory Government. But some of the Irish including Saddlier and Keogh accepted posts in the subsequent coalition Government. Moore looked on M.P's who accepted appointment as traitors to their country.
Moore was elected again in 1857 but was disqualified by petition claiming priestly intimidation. George Henry again invaded England in 1861 with his great sprinter "Croagh Patrick" and won the Stewards' Cup at Goodwood and Chesterfield Cup two days later. He sold his horses in 1869 and contested the General Election successfully. He joined the Fenian brotherhood around this time. During the life of George Henry, O'Donovan Rossa and also the future Cardinal Newman were frequent visitors to Moorehall.
George Henry Moore died on 19th April 1870 in the midst of a dispute over reduction on rents which his Ballintubber tenants were demanding. Fr. Browne officiated at the funeral ceremonies. The coffin was borne by sixteen tenants to Church at Carnacon. Not many gentry were at the funeral but the poor came from all over Mayo. He was buried in Kiltoom. Father Lavelle (the Land League priest) delivered the oration at the graveside.