Complex sentence: Rogers was promoted to temporary first lieutenant in December 1943, and returned to West Point as an instructor of economics, government, and history, from 1944 to 1945, receiving a promotion to temporary captain in February 1945.
Split into simpler sentences: Rogers was promoted to temporary first lieutenant in December 1943. He providee instruction in economics, government, and history from 1944 to 1945, and received promotion to temporary captain in February 1945.