Complex sentence: It was one of four understrength divisions on occupation duty in Japan alongside the 1st Cavalry Division, 7th Infantry Division, and 25th Infantry Division, all under control of the Eighth United States Army.
Split into simpler sentences: It was one of four understrength divisions on occupation duty in Japan. The others were the 1st Cavalry Division, 7th Infantry Division, and 25th Infantry Division, all under control of the Eighth United States Army.