|Ohio is the seventh largest state of the United States in terms of population. According to an estimation in 2008, it was inhabited by as many as 11.4 million residents in an area of 44,825 square miles. It also ranks high in population density with its position being ninth among most densely populated states of the country. Located in the Midwestern region of the US, Ohio is bordered by Indiana to the west, Pennsylvania to the east, Kentucky to the south, Michigan to the northwest and West Virginia to the southeast. It also has an international boundary with the Canadian province of Ontario to the north. The Ohio river defines its southern border while its northern border is largely defined by Lake Erie. Ohio is a transportation hub and its highway network ranks tenth across all the states of the US. The highest point in the state is Campbell Hill with a height of 1,550 feet while the lowest point goes as deep as 455 feet in the Ohio river. Humid continental climate prevails in most part of the state with the exception of some portion in the south, which lies on the northern periphery of the humid subtropical climate. Ohio became the 17th state of the US in 1803. Columbus is the capital as well as the largest city of the state.