In 1800, the United States was made up of 16 states, all east of the Appalachians, and most people lived within 50 miles of the Atlantic. Oceans and rivers were the nations' highways, providing the only viable way to travel long distances. During the 19th century, as the United States expanded across the continent, the transportation landscape changed. Roads, steamboats, canals, and railroads helped link different regions together and spread settlement away from the coast.