The Illinois Historic Preservation Agency’s efforts to preserve and promote the state’s heritage paid off in 2016 with 25 properties being added to the National Register of Historic Places, including the Downtown Aledo Historic District. Sites are added to the register by the National Park Service based on recommendations from the Illinois Historic Preservation Agency, which houses the state’s Historic Preservation Office. The National Register of Historic Places is the official list of sites that merit special attention and preservation. In general, properties have to be more than 50 years old to be eligible for the National Register. A listing places no obligations on private property owners but does make properties eligible for some financial incentives. The state historic preservation agency recognized the downtown area—founded in 1855, for a variety of architectural styles represented and specifically cited the Mercer County Courthouse, Mercer Carnegie Library, Aledo Opera House and the Aledo Depot.