George W. Bush narrowly defeated Al Gore in the 2000 presidential election after a recount in Florida determined Bush the winner. In 2001, the 9/11 terrorist attacks occurred when Al Qaeda hijacked and crashed four planes - two into the World Trade Center towers, one into the Pentagon, and one crashed in a field in Pennsylvania, killing nearly 3,000 people. In 2003, the United States invaded Iraq in search of weapons of mass destruction and to change its government, and Saddam Hussein was captured and executed that same year.