Fort Jesup became part of the claims of both the United States and Spain. When the Louisiana Purchase Treaty of 1803 failed to clearly define the western boundary of Louisiana, the United States and Spain claimed the area as their own. The dispute gave rise to the "Neutral Ground," an area where the laws of neither nation were enforced. Soldiers and settlers were kept out, and rogues and outlaws ruled the region.
After the territorial boundary was finally fixed at the Sabine River by the Florida Purchase Treaty of 1819, the United States built Fort Jesup in 1822. Lieutenant Colonel Zachary Taylor established and commanded the garrison, and Taylor's troops managed to establish law and order in the Neutral Ground. Fort Jesup remained an important military post for nearly 25 years.
Fort Jesup State Historic Site is open for tours 9am-5pm, Tuesday through Saturday.