 He moved to Monaghan in 1918 where he worked as a clerk for the Great Northern Railway Company, based in Clones.It was there that he met Eoin O'Duffy and the two became friendly with Hogan first joining the GAA and later the Irish Volunteers.During the War of Independence he quickly rose in the ranks to become second in command to Eoin O’Duffy in the Monaghan area.