city, capital of Iowa, U.S., and seat (1845) of Polk county. The city lies on the Des Moines River at its juncture with the Raccoon River in the south-central part of the state. Situated in the heart of the Corn Belt, it is the focus of Iowa's most populous metropolitan area, which includes the cities West Des Moines, Urbandale, and Pleasant Hill.

Fort Des Moines was established in 1843 at the confluence of the two rivers to protect the rights of the Sauk and Fox peoples who then inhabited the region. The area was opened to settlers in 1845. The community grew rapidly and became a city in 1857, the word “Fort” being dropped from the name. When the state capital was moved there from Iowa City later that year, its continued growth was assured. The origin of the city's place-name is controversial: it is possibly a French corruption of the Algonquian name for the river, Moingona; alternatively, it may be derived from the French de moyen (“middle”), being midway between the Missouri (Missouri River) and Mississippi (Mississippi River) rivers, or perhaps it was a reference to the Trappist monks (moines de la Trappe) who once lived at the mouth of the Des Moines River.

From 1910 to 1920 Des Moines expanded rapidly as local coal deposits were developed. The state's largest city, it is a communication hub and also a major insurance, retailing, manufacturing (notably tires and farm implements), governmental, and publishing centre (especially for farm journals). Des Moines is the site of Drake University (1881), Grand View College (1896), Des Moines University Osteopathic Medical Center (1898), and AIB College of Business (1921).

The capitol building (1871–86), built in the Greek Revival style, stands on 165 acres (67 hectares) of grounds, and the State of Iowa Historical Building houses the state archives and history museum. Cultural institutions include the Civic Center, housing the city's symphony orchestra and ballet company; the Des Moines Arts Center, with a collection of 19th- and 20th-century painting and sculpture; and the Science Center of Iowa, which includes a planetarium. Several Victorian-style mansions are open for tours, including Hoyt Sherman Place (1877), Terrace Hill (1869), and the Wallace House (1870s), the home of statesman Henry Wallace (Wallace, Henry A.). Salisbury House is a replica of the Tudor-style King's House in Salisbury, England.

Also in the city are the Iowa State Fair Grounds with Heritage Village (displaying early farm machinery and replicas of pioneer buildings) and the Iowa Museum of Agriculture. The annual state fair, held in August, is the city's premier event, drawing hundreds of thousands of visitors. Living History Farms in Urbandale (northwest) is an outdoor historical museum replicating the homes and activities of 19th-century settlers and of the Native Americans who once occupied the area. Inc. town, 1851; city, 1857. Pop. (1990) city, 193,187; Des Moines MSA, 392,928; (2000) city, 198,682; Des Moines MSA 456,022.