The first residents of Iowa, like those of Indiana, were prehistoric Mound Builders, who had disappeared before the first European explorers found Plains and Woodland Indians living throughout the area. In 1673, Frenchmen Marquette and Jolliet (or Joliet) landed on the Iowa side of Missisippi River. The region was claimed for France by La Salle, but little activity took place. In 1762, France turned the region over to Spain. The first white settler was Julien Dubuque, a French-Canadian, in 1788. In 1800, Spain returned the area to France, who sold it to the United States as part of the Louisiana Purchase in 1803. At first, Iowa was included in the territory of Louisiana, later part of the territory of Missouri in 1812. The territory of Iowa organized in 1838. There was resistance to statehood, since under territorial administration, local taxes were not required for the support of officials. When a constitutional convention finally approved a plan for statehood in 1844, they proposed boundaries that were unacceptable to Congress. The boundaries were redrawn and Iowa finally entered the Union as the 29th state, in 1846. The capital was moved to Des Moines under the provisions of the constitution adopted in 1857. Settlers in Iowa generally opposed slavery and Iowa remained loyal to the Union during the Civil War. The first railroad reached Iowa in 1867, and by 1870, there were four of them crossing the state. Iowa farmers objected to the rates being charged and succeeded in forcing the Iowa legislature to take action. Iowa was one if the first states to adopt Prohibition, going partly dry in 1855 and more completely in 1885. Between then and 1919, Iowa gradually loosened restrictions on alcohol, but the trend was overriden by the adoption of the Volstead Act, which instituted Prohibition nationwide. Although agriculture remains the mainstay of Iowa's economy, larger farms employ fewer people and by 1960, for the first time more Iowans lived in cities than in rural areas.