 He was the Boston representative at an exhibit at the MOMA in 1933 and a regular at his hometown museum, the Concord Art Association.Allen crafted the small and popular Beaux-Arts style bronzes, medical models for Harvard using the "lost wax" process, memorial tablets, portrait busts, portrait reliefs, "imaginative" pieces, garden fountains and life and death masques, as well as large memorials and architectural installations.His best-known large work is the pediment and statues atop the Supreme Courthouse in Manhattan.