AP

It's over.

After almost nine years, the United States has officially ended its Iraq campaign.

The U.S. military lowered the flag of the U.S. forces-Iraq Thursday, symbolizing the end of the war.

Now, only a few thousand troops remain in the country, a stark drop from the 170,000 once stationed there, with virtually all expected to leave by the end of the month. At the height of the war, there were 500 U.S. military installations open in Iraq--now, just two U.S. bases remain.

The war concludes with a heavy price tag: 4,500 Americans dead, 32,000 wounded, and $8 billion spent. Over a million soldiers cycled through the country at some point during the war's duration. U.S. Defense Secretary Leon Panetta acknowledged the toll the war took, but said soldiers should be proud of their accomplishments.

"We spilled a lot of blood there," Panetta said. "But all of that has not been in vain. It's been to achieve a mission making that country sovereign and independent and able to govern and secure itself."

The full legacy of the conflict will likely remain a point of controversy for generations to come.

Four thousand troops will remain in Kuwait past Christmas to help finalize the move out of Iraq--and will be on hand in the instance that reaction forces were needed.