Several years after the conclusion of the War of 1812, the U.S. military began excursions into the Spanish owned territory of Florida. In 1816, General Andrew Jackson ordered his military to invade and destroy the “Negro Fort” on the Apalachicola River because it was populated by the Seminole and runaway slaves who he believed needed to be dealt with to make way for American settlers. This was a catalyst of the Seminole War. In 1818, Jackson and his military invaded Florida and constructed Fort Gadsden atop the ruins of the “Negro Fort” that was destroyed two years earlier. From Fort Gadsden, Jackson launched the First Seminole War. The Spanish were ill equipped to defend their territory of Florida as Jackson easily took two Spanish fortifications in Pensacola and St. Marks. No longer able to protect their land, the Spanish agreed to surrender the region to the United States in the Adamas-Onis Treaty of 1819. This seemed to reconcile the matter of Americans’ right to settle the land.