The United States seized the land that comprises Oklahoma as part of the Louisiana Purchase of 1803. Throughout the 19th century, the U.S. government relocated Indian tribes from the southeastern United States to the area, and by 1900 over 30 Indian tribes had been moved to what was originally called the Indian Territories.

At the same time, ranchers in Texas began to move into the area in search of new pasture lands. The government eventually opened the land to settlement, creating “land runs” in which settlers were allowed to cross the border at a particular hour to claim homesteads. Settlers who broke the law and crossed the border sooner than allowed were called “sooners,” which eventually became the state’s nickname.

Oklahoma became the 46th state in 1907, following several acts that incorporated more Indian tribal land into U.S. territory. After its inclusion in the Union, Oklahoma became a center for oil production, with much of the state’s early growth coming from that industry. During the 1930s, Oklahoma suffered from droughts and high winds, destroying many farms and creating the infamous dust bowl of the Great Depression era.

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Oklahoma’s Original Residents

Humans arrived in the area now known as Oklahoma an estimated 30,000 years ago and organized into agriculture-based settlements around 2,000 years ago. Historians can trace the Wichita and the Caddo back 2,000 years, and the Osage and Apachean-speaking people were likely in the area before Europeans arrived.

By the time Spanish explorers came to Oklahoma in the 1500s, the area was also home to the Pawnee, Quapaw and Osage. The Kiowa, Comanche, Arapaho and Cheyenne tribes also raided the region and used its land.

The Wichitas, Caddos, Apaches and Quapaws are considered the area's Indigenous tribes. A total of 39 American Indian tribes are headquartered within Oklahoma.

European Exploration and American Settlement

A number of Spanish explorers living in Mexico first came to Oklahoma in the 1500s in search of the fabled seven golden cities. In 1539, Hernando de Soto traveled through Florida into Arkansas and potentially the eastern edge of Oklahoma searching for gold. Francisco Vásquez de Coronado journeyed from New Mexico through Texas and Oklahoma in 1541 before arriving at his destination of Kansas. Upon finding no gold, he returned to Mexico.

In the early 1700s, several French adventurers explored Oklahoma. The French established trading partnerships with the Wichita, Osage, Pawnee and other Native American tribes in the region and began vying with the Spanish for control of eastern Oklahoma and surrounding states. However, by the beginning of the 1800s, no Europeans had settled in the Oklahoma region.

Oklahoma only became part of the United States in 1803 with the Louisiana Purchase, first as part of the Territory of Louisiana and later within the Territory of Arkansas. In signing the Louisiana Purchase, President Thomas Jefferson envisioned part of the land as a reservation for Native Americans east of the Mississippi River. By 1820, the federal government had chosen the area now known as Oklahoma as its so-called “Indian Territory.”

Indian Removal Act

Throughout the early 1800s, state governments had already begun to sign treaties that forced various Native American tribes to give up their homelands. On May 28, 1830, President Andrew Jackson centralized and sped up the process by signing the Indian Removal Act. The act enabled the president to negotiate removal treaties with Native American tribes east of the Mississippi River, which forced them to give up their lands and move to “Indian Territory,” or present-day Oklahoma. The main groups impacted included the Cherokee, Muscogee, Choctaw, Chickasaw and Seminole tribes. These groups lived on a coveted 25 million acres of strategic land holdings, mainly in the states of Georgia, Tennessee, Alabama, Mississippi and North Carolina.

The tribes initially resisted removal, sending delegations to Washington, D.C. and engaging in warfare. The United States military forcefully removed tribes that refused to relocate. By 1840, nearly 100,000 Indigenous people were evicted and nearly 15,000 died of disease, exposure to elements or malnutrition along the five to six-month journey to Indian Territory. Some tribes lost up to one-third of their members, often the elderly and children. This forced eviction became known as the “Trail of Tears,” which ultimately took around 28 years to complete.

By 1883, Oklahoma had established 25 reservations for 37 tribes. Tribes that had once been nomadic and those that had never met each other were forced to settle in close proximity in boundaries created by the government. At first, Indian Territory covered most of modern-day Oklahoma, and tribes were promised that they would continue to own this territory. But land runs, auctions and allotments that gave land to settlers and railroad companies soon chipped away at the space. Indian Territory diminished to the eastern half of the state, while the western half became Oklahoma Territory.

Of the many tribes in Indian Territory, the Cherokee, Choctaw, Chickasaw, Creek and Seminole nations became recognized as the “Five Civilized Tribes.” They received this name as they began assimilating to European cultural standards, including adopting Christianity, centralized government, literacy and slaveholding (many of these elements existed in their societies well before their forced removal). On February 8, 1887, the Dawes Act created a federal commission that determined which individuals in the Five Civilized Tribes would be qualified to apply for citizenship and an assignment of tribal land from the federal government. Those who didn’t make the cut lost their land.

Oklahoma Land Rush and Statehood

Toward the end of the 19th century, a growing number of white farmers and cattle ranchers moved into Oklahoma, driven by the concept of “Manifest Destiny.” The Homestead Act, which promised private citizens up to 160 acres of unassigned public lands, was applied in Oklahoma starting in 1889. Around the same time, the Curtis Act of 1898 weakened and dissolved tribal governments, putting them under federal government control.

In March 1889, President William Henry Harrison issued a proclamation to settle unassigned lands in Indian Territory; This led to the Oklahoma Land Rush of 1889, with land runs by new white settlers vying for Native American lands. Land auctions gave away more Native American land to settlers.

By 1905, all available Native American lands had been opened to settlement. Desperate to preserve their territory, representatives from the Five Civilized Tribes submitted a constitution for a separate Native American state called Sequoyah. Although a large majority of voters supported the petition in the November election, Congress refused to consider the request for statehood. President Theodore Roosevelt declared that the Oklahoma Territory could only enter the Union if it did so jointly with the Indian Territory. On November 16, 1907, the Indian and Oklahoma territories combined to form the state of Oklahoma, the 46th state admitted to the Union.

Dust Bowl

As more settlers moved into Oklahoma and other parts of the southwestern Great Plains region, the many farmlands and cattle ranches they established destroyed native prairie grasses. When a massive drought hit Oklahoma in 1930, strong winds whisked up the arid, over-farmed and over-grazed land, darkening the skies with dust and rendering much of the land un-farmable. Oklahoma became one of the most impacted areas of what became known as the Depression-era “Dust Bowl.”

Between 1930 and 1940, refugees from 19 Dust Bowl states began fleeing westward, mainly to Arizona and California. Disdainful locals rejected many poor and homeless refugees, and "Okie” soon became a term of disdain used to refer to any poor Dust Bowl migrant, regardless of their state of origin. John Steinbeck famously chronicled the phenomenon in his Pulitzer-prize-winning novel, Grapes of Wrath. By the end of the Great Depression decade, Oklahoma had lost a net total of 440,000 residents. 

Slavery to the Civil Rights Movement

In the late 18th century, the Five Civilized Tribes throughout the United States welcomed hundreds of escaped slaves into their ranks as free people. Some Native Americans also purchased slaves, who accompanied them in the fields. When these tribes were forced to move to Indian Territory (Oklahoma) in the 1830s, they brought their slaves. At the outbreak of the Civil War, Black people made up more than 14 percent of the Indian Territory population.

During the Civil War, the nations of the Indian Territory sided with the Confederacy. Free Black Americans, called “Buffalo Soldiers” by Native Americans, joined both the Confederate and Union armies. After the Union army defeated the Confederates in Indian Territory at the battle of Honey Springs on July 17, 1863, the area remained lawless until the war’s conclusion.

After the Civil War’s end, the Five Nations abolished slavery in 1886, and former slaves were offered citizenship and land rights. After Indian Territory opened up to settlers in the late 19th century, more African Americans moved to Oklahoma to claim land. Some attempted to create All-Black towns where African Americans could live free of segregation and racial prejudice. Between 1865 and 1920, more than 20 all-Black towns were created in Oklahoma—more than any other state in the Union. Today, 13 Black towns still remain.

This growing Black population stirred up racist sentiments. Shortly after Oklahoma joined the Union in 1907, the state legislature passed Jim Crow laws that enforced racial segregation of schools and public transportation and essentially disenfranchised Blacks, who began fleeing to the west, Mexico and Canada. Starting in 1911, white Oklahomans began trying to block the migration of Blacks to the territory. Racial tensions peaked with the 1921 Tulsa Race Massacre when hundreds of Black people were killed, and the Black District of Tulsa was burned to the ground. More Black residents left during the Great Depression and Dust Bowl era, and some Black towns began to shutter.

The major achievements of the Civil Rights Movement in Oklahoma were two Supreme Court cases in 1948 and 1950, Sipuel v. Board of Regents of the University of Oklahoma and McLaurin v. Oklahoma State Regents. These cases paved the way for the outcome of Brown v. Board of Education. Oklahoma schools were desegregated in the early 1960s, and numerous Black politicians were elected to office during the decade.

Oil and agriculture

As early as 1830, oil prospectors discovered Oklahoma’s many oil springs, which at the time they considered to be medicinal. Oil drilling began in the 1870s, and the early 20th century saw many new oil discoveries. Between 1900 to 1935, Oklahoma produced more oil than any other mid-continent state. Although oil production dropped precipitously in the 1980s and 1990s, it has since picked up and remains an important part of the state’s economy. Oklahoma is among the largest producers of marketed natural gas and crude oil in the United States.

As soon as the first white settlers arrived in Oklahoma in the 19th century, agriculture and cattle ranching became the heart of the state’s economy. The number of farmers declined significantly after World War II, and the industry became less important to the state’s economy. However, Oklahoma is still one of the states with the most farms, covering more than 35 million acres of land.

Date of Statehood: November 16, 1907

Capital: Oklahoma City

Population: 3,959,353 (2020)

Size: 69,899 square miles

Nickname(s): Sooner State

Motto: Labor Omnia Vincit (“Labor Conquers All Things”)

Tree: Redbud

Flower: Oklahoma Rose

Bird: Scissor-Tailed Flycatcher

Interesting Facts

  • During the course of the day on June 8, 1974, Oklahoma City was struck by five different tornadoes. Between 1890 and 2011, the city, which is located near the heart of “tornado alley,” was hit by a total of 147 tornadoes.
  • Oklahoma’s state capitol building is the only capital with an oil well directly underneath it. In 1941, the “Petunia Number One” well was slant drilled through a flowerbed to reach the oil pool, which produced approximately 1.5 million bbl. over the course of 43 years.
  • Oklahoma is a Choctaw Indian word that means “red people.” It is derived from the words for people (okla) and red (humma).


Oklahoma Historical Society, Prehistoric Native Peoples.

Oklahoma Historical Society, American Indians.

National Archives, President Andrew Jackson's Message to Congress 'On Indian Removal' (1830).

Oklahoma Historical Society, Removal of Tribal Nations to Oklahoma.

National Archives, Background on the Dawes Commission.

Oklahoma Historical Society, Five Civilized Tribes.

Oklahoma City Public Schools, From Trails to Truths: Oklahoma History from a Native American Perspective.

Oklahoma Historical Society, Land Run of 1889.

Oklahoma Historical Society, Curtis Act (1898).

Oklahoma Historical Society, European Exploration.

Oklahoma Historical Society, Westward Expansion, 1803–1861.

Oklahoma Historical Society, Settlement Patterns.

Oklahoma Historical Society, Homestead Act (1862).

Oklahoma Historical Society, Okie Migrations.

Oklahoma Historical Society, Dust Bowl.

Library of Congress, The Dust Bowl.

Oklahoma Historical Society, Slavery.

Oklahoma Historical Society, The Civil War Era.

Oklahoma Historical Society, The African American Civil Rights Movement.

The University of Tulsa, Oklahoma: Home to More Historically All-Black Towns than Any Other U.S. State.

Oklahoma Historical Society, All-Black Towns.

Oklahoma Historical Society, Civil Rights Movement.

Oklahoma Historical Society, Petroleum Industry.

U.S. Energy Information Administration, Oklahoma State Energy Profile.

Oklahoma Historical Society, Farming.

Oklahoma Farm Bureau, Oklahoma Agriculture at a Glance.

National Weather Service, Tornadoes in the Oklahoma City, Oklahoma Area Since 1890.