On March 19, 2003, the U.S. initiated war on Iraq with what it called a massive "shock and awe" bombing campaign that lit up the skies, laid waste to large sections of the country and paved the way for American ground troops to converge on Baghdad. Watch the video above for more.The invasion was based on claims that Saddam Hussein had secretly stashed weapons of mass destruction. No weapons of mass destruction were found in Iraq.Just after the explosions began, U.S. President George W. Bush said in a televised address on March 20, "At this hour, American and coalition forces are in the early stages of military operations to disarm Iraq, to free its people and to defend the world from grave danger."The U.S., along with coalition forces primarily from the United Kingdom, was able to capture Iraq’s major cities in just three weeks.Saddam went into hiding soon after the American invasion. After an intense manhunt, U.S. soldiers found him in December 2003, just miles outside his hometown of Tikrit. He was arrested and began trial for crimes against his people, including mass killings. He was found guilty of crimes against humanity and was executed on Dec. 30, 2006.The U.S. declared an end to the war in Iraq in 2011, nearly 10 years after the fighting began. By the time the war ended, tens of thousands of Iraqi civilians were dead, along with 4,487 American troops.American forces remain in the country as a show of commitment to the region and a hedge against Iranian influence and weapons trafficking.The Associated Press contributed to this report.