The last U.S. combat troops left Iraq and crossed into Kuwait Wednesday evening, NBC reported, ending a war that lasted almost seven and a half years. 

Convoys of combat troops began leaving the country at about 6:30 p.m. on the east coast and about 1:30 a.m. in Iraq, ahead of President Obama's Aug. 31 deadline to end combat operations.

Over the course of the conflict, 4,415 U.S. service members have died and close to 32,000 were wounded.

The end of combat operations ends a war that began in 2003 under President George W. Bush. The war came to define Bush's presidency and led to heated dispute between Republicans and Democrats during his administration.

One of then-Sen. Barack Obama's major campaign promises was to end the Iraq war. 

Some U.S. troops will remain in the country for the next 16 months — 50,000 soldiers will remain in the country for training and support purposes. Approximately 56,000 troops remain in the country, according to reports, meaning that 6,000 must leave to meet Obama's deadline.

The remaining combat troops are leaving at a time when the Iraqi political system still faces uncertainty and the security situation remains tenuous. But the 2007 troop surge, enacted under Bush, was considered by many to have stabilized the country by neutralizing insurgent groups.