The first European to reach Arkansas was the Spanish explorer Hernando de Soto in the middle of the 16th century. Arkansas is one of several U.S. 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, probably a phonetic spelling of the Illinois word for the Quapaw people, who lived downriver from them.

Other Native American nations that lived in Arkansas prior to the westward movement of peoples from the East were the Quapaw, Caddo, and Osage nations. While moving westward, the Five Civilized Tribes inhabited Arkansas during its territorial period.

The region was organized as the Territory of Arkansas on July 4, 1819, but the territory was admitted to the Union as the State of Arkansas on June 15, 1836, as the 25th state and the 13th slave state.

Arkansas Chartered two banks during it's first legislative session, a State Bank and a Real Estate Bank. Both would fail within a decade and the bonds they had issued became entangled in legally questionable deals. They would come to be known as the "Holford Bonds" because they eventually which fell into the hands of a London Banker named James Holford. The issue of weather or not the bonds were a legitimate state debt and whether or not they would be repaid would be a political issue in the state throughout the 1800s.

When the Mexican-American War began in 1846, Washington became a rendezvous for volunteer troops. Governor Thomas S. Drew issued a proclamation calling on the state to furnish one regiment of cavalry and one battalion of infantry to join the United States Army. Ten companies of men assembled here where they were formed into the first Regiment of Arkansas Cavalry. In 1847 a fireball impact created a huge crater. It is thought to be a meteorite.

Arkansas refused to join the Confederate States of America until after United States President Abraham Lincoln called for troops to respond to the Confederate attack on Fort Sumter, South Carolina. The state was unwilling to fight against its neighbors and seceded from the Union on May 6, 1861. While the state was not a chief battleground, it was the site of numerous small-scale battles during the American Civil War. When Union forces captured Little Rock in 1863, the government relocated to the town of Washington in the southwest part of the state. Natives of during the Civil War included Confederate Major General Patrick Cleburne. Considered by many to be one of the most brilliant Confederate division commanders of the war, Cleburne was often referred to as "The Stonewall of the West." Also of note was Major General Thomas C. Hindman. A former United States Representative, Hindman commanded Confederate forces at the battles of Cane Hill and Prairie Grove.

Under the Military Reconstruction Act, Congress readmitted Arkansas in June 1868. With the right to suffrage, freedmen began to participate vigorously in the political life of the state. From 1869 to 1893, more than 45 African American men were elected to seats in the state legislature. As in other states, they were already leaders in their communities: often ministers or teachers, or literate men who had returned from the North. Some had both white and African-American ancestors.

In 1874, the Brooks-Baxter War shook Little Rock. The dispute about the legal governor of the state was settled when President Ulysses S. Grant ordered that Joseph Brooks to disperse his militant supporters.

The growth in industrial jobs in the North and Midwest attracted many blacks from the South in the first half of the 20th century. Their migration out of the South was a reach toward a better quality of life where they could vote and live more fully as citizens. Agricultural changes also meant that farm workers were not needed in as great number. Thousands left Arkansas. During the years of World War II, blacks also migrated to California, where good jobs were expanding in defense industries.

In one of the first major cases of the African-American civil rights era, the Supreme Court ruled in Brown v. Topeka Board of Education (1954) that segregated schools were unconstitutional. Both of Arkansas' U.S. Senators (J. William Fulbright and John L. McClellan) and all six of its U.S. Representatives were among those who signed the Southern Manifesto in response.

The Little Rock Nine incident of 1957 centered around Little Rock Central High School brought Arkansas to national attention. After the Little Rock School Board had voted to begin carrying out desegregation in compliance with the law, segregationist protesters physically blocked nine black students recruited by the NAACP from entering the school. Governor Orval Faubus deployed the Arkansas National Guard to support the segregationists, and only backed down after Judge Ronald Davies of U.S. District Court for the Eastern District of Arkansas granted an injunction from the U.S. Department of Justice compelling him to withdraw the Guard.

President Dwight D. Eisenhower, on the request of Little Rock Mayor, deployed the 101st Airborne Division to Little Rock and federalized the Arkansas National Guard to protect the students and ensure their safe passed to school. Little Rock's four public high schools were closed in September 1958, only reopening a year later. Integration across all grades was finally achieved in fall 1972.

Bill Clinton, born in Hope, Arkansas, served nearly twelve years as the 40th and 42nd Arkansas governor before being elected president in the 1992 election