[5] Bagwell became an independent member of Seanad Éireann in the Irish Free State in 1922, and held that office until 1936.

[3] During the Irish Civil War he was kidnapped from near his house in Howth and held hostage by anti-Treaty forces in the Dublin Mountains.

The Free State government responded by issuing a proclamation to the effect that if Bagwell were not safely released, reprisals would be taken.

[8][9] Bagwell, however, maintained that he escaped his captors through his own efforts and his safe release could not be attributed to these threats.

[10] At around the same time, the family residence at Marlfield House, Clonmel, County Tipperary, was burned by anti-Treaty forces and the library of rare historical documents destroyed.