A second Mississippi Freedom Trail marker is being placed at Jackson State University, where police killed two students and injured a dozen during protests in 1970.
At the time of the shooting, the school was known as Jackson State College.
The students were killed there less than two weeks after National Guards soldiers killed four students in similar protests at Kent State University in Ohio, which first captured national attention.
The original marker was placed in front of Ayers Hall in April.
The second marker was being placed Thursday on Lynch Street across from the JSU's Rose E. McCoy Auditorium.
The Mississippi Freedom Trail Marker Program commemorates the state's civil rights heritage.