How long did it take US and coalition forces to invade Iraq and topple Saddam Hussein's regime?

It took little more than three weeks for the US Army to overthrow Iraq's Ba'athist Regime. The reason that the Iraq War dragged on for nearly a decade and Iraq is now in the midst of a massive civil war over 13 years later is that the remnants of the regime and local militias began an intense guerrilla campaign to drive out the American-led Iraqi Government.