Complex sentence: It was reported the other nine soldiers who were awarded the medal posthumously, but unbeknownst to the public, Major General William F. Dean, who had been awarded the medal for actions in the Battle of Taejon, was actually a prisoner of war in North Korea.
Split into simpler sentences: It was reported the other nine soldiers who were awarded the medal, were done so posthumously. Unbeknownst to the public, Major General William F. Dean, who had been awarded the medal for actions in the Battle of Taejon, was actually a prisoner of war in North Korea.