Born at Lower Glanmere, in County Cork in Ireland, Allen moved to Bristol with his parents at an early age.
He later emigrated to the United States, where he trained as a boilermaker, but after some years, he returned to Bristol, finding work with the Steam Navigation Company.
The union became part of the United Society of Boilermakers and Iron and Steel Shipbuilders (USB), and Allen served as the secretary of its Bristol branch in his spare time.
In light of this improved position, Allen asked the union to increase his wages, to match what Brogden had been paid.
The union's members voted against this proposal, leading Allen to resign, but he was persuaded to stand in the resulting election, on a platform of being paid at the rate he had previously requested.