Early immigrants to what is now Oklahoma included explorers, adventurers, and traders who made the country conscious of the new territory, and Indian tribes forcibly removed from the East and Midwest. The interior plains of Oklahoma remained basically unchanged until white settlers came in the late 1880s.
Coal mining brought miners from Italy to the McAlester and Krebs area in the 1870s, and Poles migrated to Bartlesville to work in the lead and zinc smelters. British and Irish coal miners came to Indian Territory because they could earn higher wages there than in their native countries, and Czechs and Slovaks arrived from Nebraska, Kansas, Iowa, and Texas when railroad construction began. Mexicans also worked as railroad laborers, ranch hands, and coal miners before statehood. The oil boom of the early 20th century brought an influx of workers from the eastern and Midwestern industrial regions. In 1907, the population of Oklahoma was 75% rural and 25% urban; by 1990, however, 67.7% of all inhabitants resided in urban areas. Oklahoma lost population during the 1930s because of dust bowl and drought conditions, and the trend toward out-migration continued after World War II; from 1940 through 1960, the net loss from migration was 653,000. Migration patterns were reversed, however, after 1960. From 1960 to 1970 nearly 21,000 more people moved into the state than out of it. In the period 1970–80, a total of 293,500 more people came than left, the migration accounting for nearly two-thirds of Oklahoma's total increase of 466,000 persons in that decade. From 1980 to 1983, Oklahoma ranked 4th among the states with a total net gain from migration of 186,000 people. From 1985 to 1990, a net migration loss of about 95,500 was reported. Between 1990 and 1998, the state had net gains of 48,000 in domestic migration and 26,000 in international migration. In 1998, 2,273 foreign immigrants arrived in Oklahoma. The state's overall population increased 6.4% between 1990 and 1998. In the period 1995–2000, 322,500 people moved into the state and 305,613 moved out, for a net gain of 16,887, many whom were from Texas.