He became involved in the political struggle for Roman Catholic rights in the 1780s, when he was a member of the Catholic Committee from 1781. In 1784, Keogh joined in a plan for Ulster and Dublin radical elements to combine to push for Catholic franchise, and by 1790 Keogh was leading the Catholic Committee. He was part of a delegation that was denied a hearing by the Lord Lieutenant, and so they went to England to make their case for the repeal of the penal laws and extension of the vote to Catholics. They met with government ministers personally, and they received promises; however, Lord Kenmare quashed all progress. On the selection of the Protestant radical lawyer Theobald Wolfe Tone as Secretary to the Committee, he and Keogh became great friends, frequently travelling together around Ireland. Tone's nickname for Keogh was 'Gog'. By 1792, Keogh led the Catholic Convention in Dublin. He and others took their grievances to the King, and the result was the Catholic Relief Act of 1793, which gave Catholics the vote and repealed many of the penal laws. In return, Keogh made concessions on behalf of the Catholic Committee: they would not press for independence, and they would dissolve the committee. Keogh was criticized sharply for making these concessions, and conservatives in England were unhappy with the Relief Act. In 1795, Earl Fitzwilliam, who had favored Irish Catholic causes, and tried to extend their involvement in politics, was recalled as Lord Lieutenant of Ireland and replaced with a conservative. When another delegation headed by Keogh went to London, it got no aid and little audience. Keogh's authority and influence in the Catholic movement in Ireland decreased as newer leaders emerged, though he remained on the Dublin committee of the United Irishmen into 1798. Although he was frequently arrested and searched, Keogh was a moderate radical, and he used his wealth to aid his co-religionists' cause without crossing the line to overt illegality. He was on the non-violent wing of the United Irishmen, along with Thomas Addis Emmet. Days before the outbreak of the 1798 Rebellion, in despair at the likely result, Keogh printed a pamphlet warning his followers in Dublin that it could not succeed.
Accusations and suspicions
Some nationalists such as Walter Cox were sceptical of Keogh's motives. Cox suggested that Keogh may have been acting as an informer under the secret service of William Pitt, in order to attain information on revolutionary activities being planned by the United Irishman.
Death and burial
He died in Dublin in 1817 and was buried in St. Kevin's Churchyard, where his grave can be seen.
