NASHVILLE (AP) — A Tennessee preservation group on Monday requested a state ruling that would block Nashville development plans at the foot of a Civil War fort.

The Friends of Fort Negley filed a petition asking the Tennessee Historical Commission to declare the 21 adjacent acres proposed for development and the fort itself as protected grounds under state law.

The filing cites Tennessee's Heritage Protection Act of 2016, which prohibits removing historical memorials on public property, unless the controlling public entity requests a waiver and the commission grants it in a two-thirds vote.

The same law has drawn criticism for making it more difficult to remove Confederate monuments on public grounds in the state.

Fort Negley is often cited as one of the most significant Civil War sites for blacks and slavery. It was built with the labor of more than 2,700 blacks after Union forces occupied Nashville in 1862.

The petition says only 300 were paid, 600 to 800 died and many could be buried on the development site, where Greer Stadium now sits unused after Nashville's minor league baseball club moved to a new stadium near downtown in 2015.

The group's petition says the site includes portions of a Union entrenchment, and possibly the remains of the contraband camp where they lived and of the later free black settlement.

"Identifying and interpreting these features onsite would tell the story of the Fort more fully and would highlight the reality that the story of the site is much broader than the star-shaped fort on the hilltop," the petition says.

The preservation group worries that the adjacent construction would further harm the condition of the fort, the proposal would set a bad precedent of public park land going into private hands, and that Fort Negley Park would be reduced to "dog park status" for about 300 planned residential units.

Mayor Megan Barry has backed a development plan on the site that would add park, retail, residential and creative space. The Cloud Hill proposal is headed by developer Bert Mathews and well-known music producer T Bone Burnett.

Before moving forward with the proposal, the city is conducting an archaeological study to see if it can find unmarked graves or artifacts onsite.

Sean Braisted, spokesman for Barry, said the city and Cloud Hill are committed to preserving the fort and improving the adjacent 21 acres, including housing options for working families in an increasingly expensive city for housing.

"We will be reviewing this petition to the Tennessee Historical Commission to determine what, if any, response is needed or appropriate," Braisted said.