The First Seminole War began in response to Andrew Jackson’s attacks into Spanish Florida against the Seminole Indians. This was not the first time the United States had made military excursions into the Spanish territory. Although Spain expressed outrage at having foreign military troops in their territory they eventually decided to cede the Floridas to the United States in 1819. Once the Adams-Onis Treaty took effect in 1821 the subsequent Second and Third Seminole Wars were attempts by the United States to drive the Seminoles out of its newly acquired territory.