The painting commemorates the earliest documented formal organization of militia forces in what is now Arkansas. On July 10, 1780, under the authority of Commandant Balthazar de Villiers, eighty-seven men assembled at Arkansas Post to be organized into two militia companies. Conducted during the American Revolutionary War under Spanish colonial rule, the muster represented an important milestone in the military history of Arkansas while illustrating the multicultural frontier society that defended Spain’s northern frontier.