Millions of people participated in the Women's March in Washington, D.C., and around the world to advocate for legislation and policies on human rights and other issues.
The U.S. House of Representatives voted 395–28 to reprimand Newt Gingrich for ethics violations, making him the first Speaker of the House to be so disciplined.
Vietnam War: The People's Army of Vietnam attacked Khe Sanh Combat Base, a U.S. Marines outpost in Quảng Trị province, South Vietnam, starting the Battle of Khe Sanh.