Colonel Hugh O'Donnell d.1799 (c.1795-96). Hamilton, Hugh Douglas 1739-1808. Colonel Hugh O'Donnell was the eldest son of Sir Neal O'Donnell of Newport, Co. Mayo, and served as M.P. for Donegal in Grattan's Parliament, 1789-99. Both he and his brother James Moore O'Donnell were strongly opposed to the Act of Union. He was dismissed form the army after voicing his opposition to this, in his maiden speech to the Irish House of Commons on 22 January 1799. He died on 1st September 1799.