After the Battle of New Orleans, Jackson lifted martial law and took his army back to Tennessee. The residents of New Orleans, while grateful for his service, still chafed about their treatment during the siege and battle. A judge fined Jackson $1,000 for slandering another judge during the siege. Jackson indignantly paid the fine–twenty years later, he gleefully accepted a gift from Congress of the $1,000 plus interest. Meanwhile, back home, Jackson declared the Hermitage the official army headquarters for the District, allowing him to work from home. People around the United States were generally much more grateful to Jackson than the people of New Orleans were, and Jackson soon began touring the country in style, accepting the accolades of a thankful nation.
On one of these victory tours, Jackson began to hear rumors about the Seminole Indians in Florida attacking settlements and using the Spanish territory there for protection. Fugitive slaves were also fleeing to the area and then launching raids on nearby plantations. By 1817, the problem became more severe as settlers continued to flood the area. Two British citizens, Alexander Arbuthnot and Robert Ambrister, exacerbated the situation by providing arms to the Seminoles and urging them to fight the Americans for their land.
When the Seminoles seized property outside Fowltown, they sealed their own fate. President James Monroe called on Jackson to lead forces into the area. Through ambiguously worded orders, Monroe may have given Jackson permission to attack the Indians within Spanish territory, but the President later denied he had done anything of the kind. Nonetheless, Jackson would not be deterred anyway. He considered the Spanish settlement in the Americas a scourge of the earth, his hatred of the Spanish second only to his hate of the British. Jackson therefore led 2,000 troops across the border into Florida, seizing the town of St. Marks. In short order, he captured both Arbuthnot and Ambrister, tried them, and sentenced them to death. Leaving two hundred troops behind to protect Fort Marks, Jackson left for Fort Gadsden. Along the way, he met little resistance from the Indians, who knew him by his vicious reputation and figured it wise not to fight him. While Jackson's actions up to this point could be defensible under international law, his next actions precipitated a major crisis. He seized the Spanish capital and the governor of Florida, announcing himself the new leader of the area until "the transaction can be amicably adjusted by the two governments." With the Spanish and Indians defeated, Jackson returned triumphantly home to Nashville.
President Monroe was left to clean up the mess: two executed British nationals, illegal seizure of Spanish land and citizens and the installation of American government on Spanish territory. Monroe's cabinet recommended that he deny any knowledge of the attack and censure or remove Jackson. The American public, however, offered the opposite opinion, and the new military campaign had only further advanced Jackson's already glowing public stature.
Jackson was, therefore, shocked when Monroe restored the Florida territory to the Spanish. The Cherokees also demanded their land back, and a government official gave them four million acres–enraging Jackson even further. He left for Washington to head off a censure drive. Heavy campaigning from Jackson and his allies led the House to vote down resolutions supporting the Monroe administration's actions. For its part, Spain sold Florida to the U.S. in 1819 for five million dollars after realizing how easily the U.S. could take the land militarily for free. Finally, the British, while upset at the killing of two of their citizens, still smarted from the War of 1812 and did not wish to enter yet another battle with the U.S.
Jackson embarked on another victory tour, visiting many ports on the Atlantic coast. Monroe offered Jackson the governorship of Florida territory in 1821, and Jackson resigned from the army to take the new post. On July 17, 1821, Jackson presided over the formal transfer of the territory to the U.S., watching as the stars and stripes were hoisted above the former Spanish capital.