Ohio
From just over 45,000 residents in 1800, Ohio's population grew at rates of over 10% per decade (except for the 1940 census) until the 1970 census, which recorded just over 10.65 million Ohioans. Growth then slowed for the next four decades. The United States Census Bureau estimates that the population of Ohio was 11,689,442 on July 1, 2018, a 1.33% increase since the 2010 United States Census. Ohio's population growth lags that of the entire United States, and Caucasians are found in a greater density than the United States average. , Ohio's center of population is located in Morrow County, in the county seat of Mount Gilead. This is approximately south and west of Ohio's population center in 1990.
Ohio
Much of Ohio features glaciated till plains, with an exceptionally flat area in the northwest being known as the Great Black Swamp. This glaciated region in the northwest and central state is bordered to the east and southeast first by a belt known as the glaciated Allegheny Plateau, and then by another belt known as the unglaciated Allegheny Plateau. Most of Ohio is of low relief, but the unglaciated Allegheny Plateau features rugged hills and forests.
The rugged southeastern quadrant of Ohio, stretching in an outward bow-like arc along the Ohio River from the West Virginia Panhandle to the outskirts of Cincinnati, forms a distinct socio-economic unit. Geologically similar to parts of West Virginia and southwestern Pennsylvania, this area's coal mining legacy, dependence on small pockets of old manufacturing establishments, and distinctive regional dialect set this section off from the rest of the state. In 1965 the United States Congress passed the Appalachian Regional Development Act, an attempt to "address the persistent poverty and growing economic despair of the Appalachian Region." This act defines 29 Ohio counties as part of Appalachia. While 1/3 of Ohio's land mass is part of the federally defined Appalachian region, only 12.8% of Ohioans live there (1.476 million people.)