He eventually entered the printing trade and, after finishing his apprenticeship with the Brooklyn Daily Eagle, he joined the Typographical Union No.
He covered the Brooklyn Navy Yard, police courts, Special Sessions, and other important assignments for the paper.
[2] In 1912, Dennen was elected to the New York State Assembly as a Democrat, representing the Kings County 10th District.
[5] He remained active in Democratic politics as an election district captain, county committeeman, and a member of the Brooklyn speakers' bureau and the Seneca Club.
He was nominated and elected back to the Assembly that year, this time representing the Kings County 4th District.
Their children were George Edward Jr., Francis Xavier, Mary Rita, John Hilary, and Elizabeth Loyola.