Oddly, the thing the public least remembers about John Quincy Adams is that he was a great diplomat and Secretary of State, very possibly the greatest Secretary of State we have ever had. Before he became the sixth President of the United States, before he became a respected elder statesman in the House of Representatives, he spent eight years as James Monroe’s Secretary of State, and accomplished three great things. He negotiated or helped negotiate the Treaty of 1818 (which paved the way for better relations between the United States and Canada), and the Adams-Onis Treaty (which obtained Florida for the United States, ending the Spanish presence east of the Mississippi, and resolved all the remaining boundary issues stemming from the Louisiana Purchase. And wrote what came to be known as the Monroe Doctrine.
(1) The Treaty of 1818
The Treaty of 1818, known formally as “the convention respecting fisheries, boundary and the restoration of slaves,” settled left-over issues from the War of 1812, secured important fishing rights off Labrador and Newfoundland, resolved standing boundary issues between the United State and the United Kingdom by setting the 49th parallel as the northern border as far west as the disputed Oregon territory, and allowed joint occupation and settlement of Oregon for ten years, later extended. The Treaty (or Convention) of 1818, along with the 1817 Rush-Bagot treaty that largely demilitarized the Great Lakes, improved relations with Great Britain and Canada
(2) The Adams-Onis Treaty
The Adams–Onís Treaty of 1819, also known as the Transcontinental Treaty or the Florida Treaty, by itself would be enough to establish Adams’ reputation.
When General Andrew Jackson, pursuing raiding Seminole Indians, invaded Spanish Florida (and hanged two British subjects), the president and all the rest of the cabinet were ready to condemn him, but Adams argued that the United States was acting in self-defense, since the Spanish had become incapable of policing that territory. Adams then negotiated a treaty with Spain that: acquired Florida unconditionally, in return for the United States agreeing to pay up to $5 million in claims by American citizens against Spain; resolved the boundary issues left over from the Louisiana Purchase in such a way as to extend U.S. territory to the Pacific Ocean; and extinguished all Spanish claims above the 42nd parallel – that is, any claim to the land that would become the Oregon territory.
(3) The Monroe Doctrine.
Put simply, the Monroe Doctrine states that, on the one hand, the United States would view as an act of aggression any effort by any European nation to colonize or intervene in the affairs of any nation in the Americas, and, on the other hand, the United States would neither interfere with existing European colonies nor meddle in the internal concerns of European countries. Pretty bold statement, for a nation without much of a navy.
By the end of 1823, the American colonies of Spain and Portugal had all gained independence except Peru and Bolivia, both of which would do so within the next two years, and the islands of Cuba and Puerto Rico, which as we have seen would remain Spanish for another three quarters of a century. But obtaining independence was one thing; maintaining it was another. Neither the United States nor Great Britain wanted to see some European power move in to fill any power vacuum that might occur. British Foreign Secretary George Canning proposed a joint British-U.S. statement opposing European interference, but the War of 1812 was too recent to make any overt cooperation with England politically popular. President Monroe issued the doctrine unilaterally, as part of his seventh annual address to Congress, even though only the British fleet could enforce it, which it did, if only tacitly.
(The British had their own reasons, chiefly to preserve access to markets that had been cut off by Spain’s trade policy, and might be cut off again should any other power gain influence. And as it turned out, the practical effect of excluding European meddling was to leave the U.S. free to meddle undisturbed. But in 1823, the disparity in strength between the States and Spanish America was not nearly so great as it would become, and in 1823 it was hoped that Spanish America might confederate in the way that thirteen of the English colonies had confederated.)
After eight years, Adams became president for four years, then, after his overthrow by the new forces of western democracy exemplified by Andrew Jackson, he served 17 years in the House of Representatives, where he took up the struggle against slavery and became known as “old man eloquent.” But it could be argued that his greatest service to his country took place in his years as another man’s Secretary of State.