A handover ceremony at a military base in Basra.
The American flag is brought down for the last time, as U.S. forces leave and hand over security responsibility to their Iraqi counterparts.
Hundreds of troops are leaving every day.
The remaining 13,000 are scheduled to be gone by the end of the year, when a bilateral security pact expires.
The U.S. mission's winding down at Camp Echo south of Baghdad.
Departing troops here say its the right time to leave.
(SOUNDBITE) (English) U.S. ARMY SERGEANT FRED FOX:
"It's time, I mean, the president and everyone is saying that it's time. So, the Iraqi government for their security plan, got everything. We did as much as we can to help them out and they're taking the leading everything. So honestly it's time for us to go home and let them take care of their won. They're doing it already, so why not step back and just watch."
The withdrawal comes nearly nine years after the U.S. invasion that toppled Iraqi leader Saddam Hussein.
Almost 4,500 U.S. troops have died since, with a far higher death toll among Iraqis.
Simon Hanna, Reuters.