The last remaining major combat unit of the U.S. military in Iraq left the Middle Eastern country on Aug. 19 as part of preparations to turn over all combat operations to Iraqi forces by Aug. 31. U.S. special operation forces and some 50,000 servicemen will remain in Iraq to help track down terrorist and to train the Iraqi forces. U.S. Sen. John Boehner (R-Ohio) said the withdrawal of U.S. combat troops from the country marks a “significant milestone for both the United States and a free and democratic Iraq,” USA Today reports.