Complex sentence: Sol Auerbach, later known by the pseudonym James S. Allen, was born in Philadelphia, Pennsylvania in 1906, the son of ethnic Jewish parents that arrived in America from the Russian empire in that same year.
Split into simpler sentences: Sol Auerbach, later known by the pseudonym James S. Allen, was born in Philadelphia, Pennsylvania, in 1906. He was the son of ethnic Jewish parents who arrived in America from the Russian Empire the same year.