The first European who arrived in Arkansas was the Spaniard Hernando de Soto, explorer at the end of the 16th century. Arkansas is one of several modern-day states formed from the territory purchased from Napoleon Bonaparte in the Louisiana Purchase. The early Spanish or French explorers of the state gave it its name, which is probably a phonetic spelling for the Illinois word for the Quapaw people, who lived downriver from them. Other Native American nations that lived in Arkansas prior to westward movement were the Quapaw, Caddo, and Osage Nations. While moving westward, the Five Civilized Tribes inhabited Arkansas during its territorial period. Prior to statehood, it was originally known as the Arkansas Territory.

On June 15, 1836, Arkansas became the 25th state of the United States as a slave state.

Arkansas refused to join the Confederate States of America until after Abraham Lincoln called for troops to respond to the provoked attack of Fort Sumter by Confederate forces in South Carolina. It seceded from the Union on May 6, 1861. While not often cited in history, the state was the scene of numerous small-scale battles during the American Civil War. Arkansans of note during the Civil War include Confederate Major General Patrick Cleburne. Considered by many to be one of the most brilliant Confederate division commanders of the war, Cleburne is often referred to as "The Stonewall of the West." Also of note is Major General Thomas C. Hindman. A former United States Representative, Hindman commanded Confederate forces at the Battle of Cane Hill and Battle of Prairie Grove.

Under the Military Reconstruction Act, Congress readmitted Arkansas in June 1868.

In 1874, the Brooks-Baxter War shook Little Rock and the state governorship which was finally settled when Grant ordered that Joseph Brooks disperse his militant supporters.

In 1881, the Arkansas state legislature enacted a bill that adopted an official pronunciation, to combat a controversy then raging around the proper pronunciation of the state's name.

After the case Brown v. Topeka Board of Education in 1957, the Little Rock Nine incident again brought Arkansas to national attention when the Federal government was forced to again interfere in the Arkansan capital. Orval Faubus, governor at the time, sent the Arkansas National Guard to aid segregationists in preventing nine African-American students from enrolling at Little Rock's Central High School. President Eisenhower sent troops to escort the African-American students on September 25, 1957. This incident eventually led to the closing the Little Rock high schools for the rest of the school year. The Little Rock high schools were completely integrated by fall 1959.