Kent State to mark place in history with unveiling of National Historic Landmark plaque on May 4 anniversary. Reported by Brandon Bounds. Kent State University will mark its place in U.S. history this Friday when it unveils a plaque designating 17 acres tied to the events of May 4, 1970, as a National Historic Landmark. The dedication is one of several events planned to mark the 48th anniversary of the day protests against the Vietnam War on campus turned deadly as the Ohio National Guard shot and killed four students and wounded nine others.