On March 2, 1819, the Arkansas Territory was authorized by an act of Congress, to take effect on July 4, 1819.
The Arkansas Territory was created from the portion of the Missouri Territory. It originally encompassed all of what is now Arkansas and much of what is now Oklahoma. The westernmost portion of the territory was removed on November 15, 1824, a second westernmost portion was removed on May 6, 1828, reducing the territory to the extent of the present state of Arkansas.
The Territorial capital was Arkansas Post from July 1819 until June 1821. At that point in time it was moved to Little Rock. In 1819, there was no permanent settlement in Little Rock. It would not be until early February 1820 that a permanent settlement would be established. On 1818, the Quapaw Treaty had anticipated a future settlement in Little Rock.