The Arkansas Territorial Militia was the forerunner of today's Arkansas National Guard. The current Arkansas Army National Guard traces its roots to the creation of the territorial militia of the District of Louisiana in 1804. As the District of Louisiana evolved into the Territory of Missouri and the first counties were organized, regiments of the Missouri territorial militia were formed in present-day Arkansas. territorial governors struggled to form a reliable militia system in the sparsely populated territory. When the Arkansas Territory was formed from the Missouri Territory, the militia was reorganized, gradually evolving from a single brigade composed of nine regiments to an entire division composed of six brigades, each containing four to six regiments. The local militia organization, with its regular musters and hierarchy added structure to the otherwise loosely organized territorial society. The Territorial Militia was utilized to quell problems with the Indian Nations and was held in readiness to deal with trouble along the border with Mexico due to an ambiguous international border and during the prelude to the Texas War of Independence.
The history of the Arkansas militia begens in 1804, when the United States bought a huge tract of land west of the Mississippi River from France. At the time of the transaction, now known as the "Louisiana Purchase", the area that would eventually enter the Union as the State of Louisiana was referred to as the District of Orleans. The area north of present-day Louisiana was referred to as the District of Louisiana. At first the new "District of Louisiana" was attached to Indiana Territory for administrative purposes. In 1804 the District of Louisiana was designated as the Louisiana Territory and the new territory was subdivided into districts – namely, St. Charles, St. Louis, Ste. Genevieve, Cape Girardeau, and New Madrid – stretching along the Mississippi River with no definite boundaries to the west. The area of the present State of Arkansas lay within the District of New Madrid, which stretched from the present Arkansas-Louisiana state line to the present city of New Madrid, Missouri. The authorities found that there were few people in the new territory, especially the area which was later to become Arkansas, to enroll in the militia. Low and swampy, early Arkansas attracted few settlers, and many of those who did come were itinerant French hunters and trappers who were hardly temperamentally fit for the militia, which required a fairly settled population. The last census conducted under French rule in 1803 "estimated" that the Arkansas Post District had a population of 600 with a militia of 150.