Complex sentence: After graduating Trinidad High School, Jack Woolf entered Texas A&M College in 1941, and in 1943 entered into active duty in the Army, became a commissioned officer in the Air Corps.
Split into simpler sentences: After graduating Trinidad High School, Jack Woolf enrolled in Texas A&M College in 1941, but in 1943 left A&M and entered into active duty in the Army. He became a commissioned officer in the Air Corps.