Complex sentence: He served in the United States Navy during World War II as an air combat intelligence officer in the Pacific Theater, and upon discharge he returned to the private practice of law with his former firm and became a partner in 1946.
Split into simpler sentences: He served in the United States Navy during World War II as an air combat intelligence officer in the Pacific Theater. Upon discharge from the service he returned to the private practice of law with his former firm and became a partner in 1946.