Complex sentence: Allen B. DuMont, formerly DeForest's chief engineer, opened pioneering TV manufacturer DuMont Laboratories in Passaic in 1937, and started the DuMont Television Network, the world's first commercial television network, in 1946.
Split into simpler sentences: Allen B. DuMont, formerly DeForest's chief engineer, opened pioneering TV manufacturer DuMont Laboratories in Passaic in 1937. DuMont later started the DuMont Television Network, the world's first commercial television network, in 1946.