Complex sentence: Born in New York City, Arthur Kornberg was the son of Joseph and Lena Kornberg who emigrated to New York from Austrian Galicia (now part of Poland) in 1900 before they were married.
Split into simpler sentences: Born in New York City he was the son of Joseph and Lena Kornberg. His parents emigrated to New York from Austrian Galicia (now part of Poland) in 1900 before they were married.