More than 3 million people (including 58,000 Americans) were killed in the Vietnam War; more than half were Vietnamese civilians. By 1969, at the peak of U.S. involvement in the war, more than 500,000 U.S. military personnel were involved in the Vietnam conflict. Growing opposition to the war in the United States led to bitter divisions among Americans, both before and after President Richard Nixon ordered the withdrawal of U.S. forces in 1973.