In March 2003, the  the  Army's 3rd Division crossed Kuwaiti border into Iraq as part of Operation Iraqi Freedom. By 4 April, the division had advanced 400 kilometers and was at the gates of Baghdad, the Iraqi capital. 

As the 3rd prepared to conduct the offensive into Baghdad, U.S. intelligence lacked a clear understanding of the state of defenses within. 

This prompted an armoured raid into the capital to test the response of the Iraqi defences - an operation that has since become known as the Thunder Run into Baghdad.