It is known as the Buckeye State, but the word Ohio actually means great in the Iroquois language. It surely applies when looking at the achievement of its residents over the past 200 plus years. Ohio produced seven U.S. presidents, two legendary astronauts, an assortment of revolutionary inventors and many other notables. The state encompasses 41,330 square miles and contains 88 counties with a population of some 11.3 million residents. The topography of the state is generally rolling plains with the Allegheny plateau located in the east. The Lake Erie plains extend southward with the central plains in the west. Ohio offers two distinct personalities to visitors. Big cities such as Cincinnati, Cleveland, Columbus, Toledo and Dayton evoke the image of industry and urbanization. But outside the metropolitan strongholds, Ohio's rural element, small towns and family farms take visitors back to simpler time. Ohio's geographic location has proved to be an asset for economic growth and expansion. Because Ohio links the Northeast to the Midwest, much cargo and business traffic passes through its borders on its well-developed highways. Ohio has the nation's 10th largest highway network, and is within a one-day drive of 50% of North America's population and 70% of North America's manufacturing capacity. To the North, Lake Erie gives Ohio 312 miles of coastline, which allows for numerous seaports. Ohio's southern border is defined by the Ohio River (with the border being at the 1793 low-water mark on the north side of the river), and much of the northern border is defined by Lake Erie. It borders Pennsylvania on the east, Michigan in the northwest near Toledo, Ontario, Canada across Lake Erie to the north, Indiana to the west, Kentucky on the south, and West Virginia on the southeast. Bounded on the east by the Pennsylvania line, on the south by the Ohio River, to the mouth of the Great Miami River, on the west by the line drawn due north from the mouth of the Great Miami aforesaid, and on the north by an east and west line drawn through the southerly extreme of Lake Michigan, running east after intersecting the due north line aforesaid, from the mouth of the Great Miami until it shall intersect Lake Erie or the territorial line, and thence with the same through Lake Erie to the Pennsylvania line aforesaid. Note that Ohio is bounded by the Ohio River, but the river itself belongs mostly to Kentucky and West Virginia. The border with Michigan, has also changed, as a result of the Toledo War, to angle slightly northeast to the north shore of the mouth of the Maumee River. Much of Ohio features glaciated 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. Known somewhat erroneously as Ohio's "Appalachian Counties" (they are actually in the Allegheny Plateau), this area's coal mining legacy, dependence on small pockets of old manufacturing establishments, and even distinctive regional dialect set this section off from the rest of the state and, unfortunately, create a limited opportunity to participate in the generally high economic standards of Ohio. Significant rivers within the state include the Cuyahoga River, Great Miami River, Maumee River, Muskingum River, and Scioto River. The rivers in the northern part of the state drain into the northern Atlantic Ocean via Lake Erie and the St. Lawrence River, and the rivers in the southern part of the state drain into the Gulf of Mexico via the Ohio and then the Mississippi. Grand Lake St. Marys in the west central part of the state was constructed as a supply of water for canals in the canal-building era of 1820¿1850. For many years this body of water, over 20 square miles (52 km²), was the largest artificial lake in the world. It should be noted that Ohio's canal-building projects were not the economic fiasco that similar efforts were in other states. Some cities, such as Dayton, owe their industrial emergence to location on canals, and as late as 1910 interior canals carried much of the bulk freight of the state.