Political prisoners were confined in Kilmainham, with many of the Irish leaders of the 1798, 1803, 1848, 1867 and 1916 rebellions held in the gaol. Robert Emmet, the leader of the 1803 rebellion against the British, was confined there prior to his execution on Thomas Street on the 20th of September 1803. Anne Devlin was Robert Emmet’s housekeeper and spent two years at Kilmainham for refusing to betray him. Thomas Addis Emmet was Robert's older brother and was held at Kilmainham in 1798. Nicholas Gray and his brother-in-law, Henry Hughes, were prisoners after the 1803 Rebellion. Robert Addis Emmet was like a father to Nicholas Gray, his wife Ellen and children, after arriving in America. There are numerous letters written by Gray located at the Fold3 website. Letters received by the Adjutant General, 1805 - 1821. Nicholas was not a naturalized U.S. citizen as of Feb 13, 1814. Several letters show there was some conflict between a few American Officers and the Irish Officers. Nicholas served throughout the War of 1812. His son was a Midshipman in the U.S. Navy. Nicholas Gray's youngest brother Loftus was a member of the British Rifle Brigade.