Oklahoma

Oklahoma, also known as the Sooner State, entered the Union on November 16, 1907, as the forty-sixth state. It is located in the western southcentral United States, surrounded by Texas , New Mexico , Colorado , Kansas , Missouri , and Arkansas . With a total area of 69,956 square miles (181,185 square kilometers), Oklahoma is the eighteenth-largest state in America.

The first explorers to visit Oklahoma were Spanish conquistadors , led by Hernando de Soto (c. 1500–1542) and Francisco Vásquez de Coronado (c. 1510–1554) in the sixteenth century. At that time, very few Native American tribes lived there. In the eighteenth century, French fur trappers paddled up the rivers of Oklahoma.

All of present-day Oklahoma became part of U.S. territory as part of the 1803 Louisiana Purchase . By that time, many Native American tribes, including the Cherokee, Chickasaw, Creek, and Seminole, had been ordered by the federal government to relocate from the southeast United States into the Oklahoma region. These tribes prospered in their new home because the soil was rich, enabling them to grow vast food crops.

Congress opened up the western part of Oklahoma to white settlers in 1889. Soon, homesteaders took control of that portion of the state while Native Americans retained control of the eastern region.

Oklahoma was an oil-producing state when it entered the Union, and it remained the U.S. leader in oil production until 1928. The state experienced great social unrest throughout the 1920s as nearly one hundred thousand residents joined the white supremacist group, the Ku Klux Klan . The following decade brought economic depression and drought, causing many residents to leave for California in hopes of finding work.

Oklahoma increased its wealth throughout the 1960s and into the early 1980s as it reemerged as a leader in the oil and gas industry. That changed in 1983, when the oil boom ended and prices fell. Farmers and bankers found themselves in financial straits while industries such as transportation and light manufacturing continued to prosper.

On April 19, 1995, domestic terrorism struck Oklahoma when the Alfred P. Murrah Federal Building in Oklahoma City was bombed. The Oklahoma City federal building bombing claimed the lives of 168 people, including children. A memorial to the victims of the bombing was erected in April 2000.

Oklahoma's population in 2006 had reached nearly 3.6 million, with 75.4 percent white, 7.4 percent American Indian or Alaska Native, and 6.6 percent Hispanic or Latino.

Agriculture dominated the state until midway through the twentieth century. At that point, manufacturing led the growth areas, followed by wholesale and retail trade, services, and finance. The oil and gas industry continues to contribute to state revenues. The state's military installations—Fort Sill and Tinder Air Force Base—are two of the top five employers in Oklahoma.