Jack Adair, a threatening man with a great black beard, had made his fortune buying up estates bankrupt after the Irish potato famine. He would evict the peasants and start with more productive tenants. After the estates became profitable, he would resell them for a profit. He was not very popular as he was heartless in the way the evicted widows, the aged and children. There are stories about him buying an estate and evicting everyone, earning him the reputation as one of the worst excesses of Irish landlordism.. When an elderly widow woman would not move, he got the sheriff to remove her and the horses stomped in her sod house so she could not return. Announcing his death, the Derry Journal asserted that ‘Who speaks but good of the dead need never name John George Adair’. See article in History Ireland.
His family is said to have moved to Ireland in 1690 because Scots were allowed to farm tax free. The story of the Rathdaire Protestant Parish Church where he is buried, will give an idea of how he was regarded at home.
One of his estates, Glenveagh Castle is a National Park today. He and Cornelia built the castle in 1867. After his death, Cornelia Adair returned to Glenveagh to stay until the beginning of World War I.