Ever since Andrew Jackson launched his invasion of Florida in 1818 to suppress British assistance to the Seminoles historians have sought to assign responsibility to either the 1815 Hero of New Orleans, President James Monroe, or both men. Prominent in that debate was the potential existence of a letter from Tennessee congressman John Rhea – who acted as a middle-man between Monroe and Jackson by informing the latter that the president authorized the invasion. The discovery in 2008 of a letter from Jackson to his wife Rachel (dated February 19, 1818) corroborating the Rhea letter’s existence laid part of that controversy to rest, but historian Daniel Feller correctly argues that “the mystery over whether Monroe did or did not unleash Jackson through John Rhea misses the real issue. The real issue is that Jackson thought he could, and that Monroe did not correct him.” For some time, historians have taken sides by assessing whether Monroe was “practicing the art of deniability” evinced by other clandestine actions during the era, or if Jackson was eschewing responsibility by creating a backstory justifying his actions.

Right: Andrew Jackson 1819 by Rembrandt Peale (Maryland Historical Society BCLM-CA.679). Source: Maryland Center for History and Culture.

Regardless, the invasion put Monroe under considerable pressure due to the fact that Jackson likely exceeded the president’s expectations by capturing almost the whole territory, and, along the way, executing two British nationals accused of aiding the Seminoles. Feller concludes that for years Monroe knew that Jackson wanted to conquer Florida, and that he would not have been naïve enough to have “expected restraint” from a general whose intentions were well known. Monroe may also have initially worried about what influential people such as the editors at the Enquirer and other major newspapers thought about the controversy, but many Americans supported the invasion.[1]

Jackson was a popular figure after his 1815 victory, but Americans were divided on launching another war. “The debate yet continues in the House of Representatives on the general question respecting the South American provinces,” the National Intelligencer reported in late March, “and grows even more animated as it proceeds. The question of war with Spain is almost as much debated as” the legislation being discussed. “How desirable it is for us to occupy Florida!” rang Richmond’s Enquirer, “Every day makes it clearer to our senses. Spain herself derives little benefit from its possession. She cannot maintain her authority within its limits. She could not exclude the British from Pensacola during the late war.” Natchez’s Mississippi Republican, a reliably expansionist newspaper, attacked “hired” Spanish propagandists in the eastern press, warning that “our fellow-citizens should no longer be dupes of our enemies,” and argued that American “friends of Mexico and South American liberty and independence” needed to “become allies of these new states and assist them” in throwing off their colonial masters. One Vermont editorial titled “Another Unnecessary War” lamented “a disposition in our rulers to declare war against Spain,” and the existence of a “general dislike, prevailing among us, of that nation and its government.” Editors at the Evening Post wondered if an invasion of Spanish soil was not in itself an act of war: “We have invaded her territory, seize and continue to hold adverse possession of it – in short, committed the most positively offensive act against her sovereignty, and yet we are not at war with her, nor she with us!”[2]

Left: "Capture of Indian Chiefs" - 1818 Florida.  Illustration of the arrest of Hillis Hadjo and Homathlemico at St. Mark's. 

Historiography linking the new secretary of state, John Quincy Adams, and Jackson, tends to focus on their presidential rivalry in the 1820s. However, among Monroe’s cabinet members, it was Adams alone who defended Jackson as having acted in self-defense, and calmly steered the administration’s response while continuing negotiations with Spanish minister Luis de Onís. “The President and all the members of the Cabinet, except myself,” Adams wrote in his diary of a July 15 cabinet meeting, believed “Jackson acted not only without, but against, his instructions; that he has committed war upon Spain, which cannot be justified, and in which, if not disavowed by the administration, they will be abandoned by the country.” Adams knew the situation was “embarrassing and complicated” but understood – after having discussed the issue with a “tractable” Onís four days prior – that “there was no real, though an apparent, violation of his [Jackson’s] instructions; that his proceedings were justified by the necessity of the case, and by the misconduct of the Spanish commanding officers in Florida.” Moreover, disavowing the actions of filibusterers and adventurers with indiscernible ties to the government was easy, but Adams believed, and Monroe soon came to understand, that they could not do the same with Jackson and expect the Spanish to cede Florida. For that reason, rather than offer apologies, requests for indemnities amounting to all the territory east of the Mississippi River were renewed, which was a prudent embrace of Jackson’s unconventional conduct during a crisis when war could have erupted had the Spanish not been so preoccupied elsewhere.[3] Ultimately, Jackson’s aggressiveness was vindicated because the 1819 Adams-Onís Treaty – known at the time as the ‘Transcontinental Treaty,’ required a newly-independent Mexico to accede to that agreement, lest it open up the possibility of renewed conflict in a contested region of North America.

[1] Daniel Feller, “2009 Catherine Prescott Lecture The Seminole Controversy Revisited: A New Look At Andrew Jackson’s 1818 Florida Campaign,” The Florida Historical Quarterly 88, no. 3 (2010), 318–9; Adams (ed.), Memoirs of John Quincy Adams, vol. 4, 118. July 25, 1818: “For the Richmond Enquirer, which Clay’s Kentucky Reporter calls the President's domestic paper, is, on the contrary, the paper by which Virginia works upon the President. Its influence is much more upon him than for him…” For the executions, see: Deborah A. Rosen, “Wartime Prisoners and the Rule of Law: Andrew Jackson’s Military Tribunals during the First Seminole War,” Journal of the Early Republic 28, no. 4 (Winter 2008): 559-595. This article is an amended excerpt from: Benjamin J. Swenson, America and the Mexican War of Independence: Insurgents, Patriots, and Brethren in Arms, 1810–1821 (Jefferson, NC: McFarland & Co, Publishers, 2025).

[2] Daily National Intelligencer, Washington DC, March 27, 1818; “South American Affairs.” The Enquirer, Richmond, April 7, 1818; “For the Mississippi Republican. Mexico and South America, No. 111” Mississippi Republican, Natchez, April 9, 1818; “Another Unnecessary War.” Spooner’s Vermont Journal, Windsor, April 13, 1818; “War with Spain; yes or no?” The Evening Post, New York, July22, 1818. 

[3] Adams (ed.), Memoirs of John Quincy Adams, vol. 4, 106–8. July 11, 15, 1818; Daniel Feller, “2009 Catherine Prescott Lecture The Seminole Controversy Revisited,” 322; “Negotiations with Spain.” The Enquirer, April 17, 1818.