The Spaniards, in their obstinate search for gold, were the first Europeans to set foot in Arkansas when an expedition led by Hernando de Soto crossed the Mississippi River in 1541. Although the conquistadores covered many miles of territory before wandering southward, they made few reliable maps or records. The region was not visited by white men again until 1673 when Jacques Marquette, along with fur trader Louis Joliet, descended the Mississippi to the mouth of the Arkansas. In 1682 La Salle took formal possession of the territory for Louis XIV of France.
La Salle, on his return form France in 1684, had sailed into the Gulf of Mexico with several ships, intending to explore northward from the mouth of the Mississippi. However, the great explorer was murdered by his own mutinous crew. Several of the men who had remained in Illinois set off southward in search of their missing leader. The rest of this group was left at the mouth of the Arkansas River to set up a camp which was to become the village of Arkansas Post, the first permanent white settlement in the lower Mississippi valley.
The entire territory became Spanish by treaty in 1763, but reverted to France in 1800. These changes had little effect on the colonists until the United States acquired the area as part of the Louisiana Purchase in 1803. A few years later the Arkansas District of Louisiana Territory was organized with headquarters at Arkansas Post. In 1812, when Louisiana became a state, the District was attached to the Missouri Territory. Plenty of free open land remained, much of which was reserved for displaced Indian tribes. The conflict that arose when some of the same land was awarded to veterans of the War of 1812 was not resolved until a new boundary was established for the Choctaw tribe in 1825 and a few years later for the Cherokee.
When Arkansas became a separate territory in 1819, Missouri was already anticipating admission as a state. Some of the land in the extreme northeastern corner of Arkansas was owned by influential men who wished to be citizens of a state rather than a territory. They were instrumental in having part of the boundary of the proposed state of Missouri moved down to include their land, thus accounting for the jog in the northeastern borderline of Arkansas.
An effort was made in Congress to prohibit the further introduction of slaves into Arkansas Territory. However, the antislavery amendment for Arkansas was defeated in the House by one vote, and slaveholding became an integral part of the Territory's economic life. The citizens were so eager for statehood that a constitution was framed even before Federal authorization had been officially received, and Arkansas was admitted to the Union as a state on June 15, 1836.