 It is housed in the historic Old City Hall (1857), a National Historic Landmark.The Oakleigh Historic Complex features three house museums that attempt to interpret the lives of people from three strata of 19th century society in Mobile, that of the enslaved, the working class, and the upper class.The Mobile Carnival Museum, housing the city's Mardi Gras history and memorabilia, documents the variety of floats, costumes, and displays seen during the history of the festival season.