* Invasion of Iraq: March 2003
* Fall of Baghdad: April 2003
* Surge in U.S. troops: 2007
* U.S. troop withdrawal: 2011
2. Barack Obama (2009-2017)
* Operation Iraqi Freedom ends: 2010
* U.S. troops remain in Iraq: 2010-2011
* U.S. forces return to Iraq: 2014
* U.S.-led coalition against ISIL: 2014-2017
* U.S. troop withdrawal from Iraq: 2016-2018