As the number of dead and wounded American soldiers in Vietnam was announced daily on the nightly news, protest marches continued across the U.S. Some of them remained peaceful while others were contentious, sometimes to the point of violence. This tension culminated in the tragic deaths of four Kent State University students on May 4, 1970 when National Guard troops opened fire on a group of protesters. The U.S. was a nation in public and private turmoil. Department of Defense, National Archives and Records Administration, NAID 594360, photo by Sgt. Albert R. Simpson 

Antiwar protests at the Pentagon
October 21, 1967