In response to these Seminole attacks, Monroe ordered a military expedition to cross into Spanish Florida and attack the Seminoles. The expedition, led by Andrew Jackson, defeated numerous Seminoles but also seized the Spanish territorial capital of Pensacola. With the capture of Pensacola, Jackson established de facto American control of the entire territory. While Monroe supported Jackson's actions, many in Congress harshly criticized what they saw as an undeclared war. With the support of Secretary of State Adams, Monroe defended Jackson against domestic and international criticism, and the United States began negotiations with Spain.