The Savannah Historic District is a large urban U.S. historic district that roughly corresponds to the pre-Civil War city limits of Savannah, Georgia. The area, at just over 2 square miles, was declared a National Historic Landmark District in 1966 and is one of the largest urban, community-wide historic preservation districts in the United States. The district was made in recognition of the Oglethorpe Plan, a unique sort of urban planning begun by James Oglethorpe at the city's founding and propagated for the first century of its growth.