Vicksburg National Military Park on Saturday will commemorate the service of African American troops in the Civil War as part of a free-admission weekend at the park.

At 7 p.m. Saturday, park ranger Dr. David Slay, who has a doctorate in history, will present a program on the Third U.S. Colored Cavalry and the Battle of Yazoo City, which took place in March 1864.

The Third USCC was part of a Federal force occupying the port at Yazoo City when they were suddenly attacked by portions of Confederate Gen. Brig. Gen. Lawrence S. Ross’s Texas Brigade.

Ross wrote that he was not prepared to recognize the blacks as soldiers “or guaranty them nor their officers protection as such.”

Doors will open at 6:30 p.m. for the program in the park’s Visitor Center.

Admission to the park is free Saturday through Monday in honor of Presidents Day, which recognize George Washington’s birthday and later unofficially included Abraham Lincoln’s birthday.

For more information, call Vicksburg National Military Park at 601-636-0583 or visit www.nps.gov/vick or www.facebook.com/vicksburgnmp.nps.