The U.S. flag is coming down in Vicksburg.

No, it’s not a new rebellion, but a symbol of what Vicksburg National Military Park interpretive ranger Tim Kavanaugh calls “the most traumatic event to ever befall our nation, that forever changed us as a people and a country, and whose issues continue to affect us to the present day.”

Mimicking events of 150 years ago, the Stars and Stripes will be lowered from the flag pole at Vicksburg’s Old Court House Museum the morning of Jan. 8, and Mississippi’s old “Bonnie Blue Flag” of independence raised.