President Obama is expected to designate much of Fort Monroe as a national monument on Tuesday according to a story in the Virginian-Pilot. The historic fort, an important Civil War landmark, was closed by the Army last month and control was passed to the state of Virginia. Preservationists have been worried that the sprawling 565-acre fort with its historic stone fortress and miles of Chesapeake Bay waterfront would fall to developers if the president didn’t act.

Interior Secretary Ken Salazar told the newspaper that Obama would use the powers granted to him under the Antiquities Act to preserve the fortress, where Confederate President Jefferson Davis was imprisoned following the Civil War, as well as a large section of the fort. The fort is also the site where escaped slaves were given protection from their masters when they were declared to be contraband of war and therefore did not have to be returned to their masters as was the law of the day.