The mission cost nearly 4,500 American and well more than 100,000 Iraqi lives and $800 billion from the U.S. Treasury. The question of whether it was worth it all is yet unanswered.
The war that began in a blaze of aerial bombardment meant to shock and awe the dictator Saddam Hussein and his loyalists ended quietly and with minimal fanfare.
The last of the soldiers whooped, fist bumped and hugged one another in a burst of joy and relief.
At least 4,000 forces will remain in Kuwait for some months to help finalize the move out of Iraq, but could also be used as a quick reaction force if needed.
Some Iraqis celebrated the exit of what they called American occupiers, neither invited nor welcome in a proud country.
U.S. officials acknowledged the cost in blood and dollars was high, but tried to paint a picture of victory - for both the troops and the Iraqi people now freed of a dictator and on a path to democracy.
However, the question remains whether Iraqis will be able to cement their new government amid the still stubborn sectarian clashes and if Iraq will be able to defend itself and remain independent in a region fraught with turmoil and still steeped in insurgent threats.
Many Iraqis are nervous about the future. Their relief at the end of Hussein, who was hanged on the last day of 2006, was tempered by a long and vicious war that was launched to find nonexistent weapons of mass destruction and nearly plunged the nation into full-scale sectarian civil war.
Some criticized the Americans for leaving behind a destroyed country with thousands of widows and orphans, a people deeply divided along sectarian lines and without rebuilding the devastated infrastructure.
The Associated Press contributed to this report.