From 1801 to 1885, the constituency comprised the whole of County Louth, except for the parliamentary boroughs of Drogheda and Dundalk.
John J. O'Kelly, a native of Kerry, resident in Glasnevin (Dublin), was Louth's first TD.
Chester resigned by accepting the office of Steward of the Chiltern Hundreds, causing a by-election.
Fortescue was appointed a Lord Commissioner of the Treasury, requiring a by-election.
Parkinson-Fortescue was appointed Chief Secretary for Ireland, requiring a by-election.