To most joggers and dog walkers in Kalorama Park, there’s little evidence of a sprawling 150-year-old plantation that once covered the three-acre site. But that might change: Yesterday, the D.C. Historic Preservation Review Board voted to grant the site landmark status, giving it more protections and higher visibility as a piece of slavery history.

On the northern two-thirds of Kalorama once stood what historians call the “Little House,” the nucleus of a 56-acre estate operated by aristocrat and slave owner John Little in the mid-19th century, when the neighborhood was a D.C. exurb. Archaeologists came upon the house’s remnants last year during a project to improve the park’s drainage system, and things got really interesting when it was discovered that the plantation saw an escape attempt—in 1861, 20-year-old Hortense Prout made a break for it and took refuge among federal troops, but was quickly recaptured and served ten days in jail before being returned to the plantation.

The Little House wound up abandoned by 1927, and had already toppled when the city built a public park on the location in the 1940s.

The site is already a part of the National Park Service’s Underground Railroad Freedom Trail, a national program to educate tourists about the importance of certain landmarks in helping American slaves achieve freedom. Now, the Board would like the site to get a spot on the National Register of Historic Places as well.

It was a special day at yesterday’s HPRB hearing—archaeological nominations don’t come around that often anymore. Long-time board member Bob Sonderman, who serves as the staff archaeologist at the National Park Service, said he hadn’t seen a case before the panel in at least ten years.