Adams-Onís Treaty (1819)

The Treaty of Paris may have brought independence to the United States in 1783, but the borders of the new nation remained somewhat ambiguous. During the colonial era, border disputes between the English-speaking colonies and their French, Spanish, Dutch, and indigenous [Page 118]neighbors provoked many conflicts and not a few wars. One long-standing dispute was the location of the border between the United States and the Spanish colonies of east and west Florida. Following independence, overlapping claims continued to cause suspicion and varying degrees of hostility between the two nations. This was exacerbated by slaves escaping into Spanish lands and the general belief among Americans residing along the border areas that the Spanish were protecting escaped slaves and inciting the Indians to raid the U.S. frontier settlements.

In 1803 the Louisiana Purchase brought further ambiguity to the western border between the United States and Spain through lack of a clear definition and faulty maps. Further, on the southern border some Americans, including President Thomas Jefferson, argued that the deal had also included Florida. Over the years the United States made several offers to purchase Florida, and in 1810 and 1812, with Spain preoccupied by the Napoleonic Wars, it annexed portions of west Florida.

In the following years, American military forces occasionally moved temporarily into Spanish territory on the justification that they were in pursuit of Indian raiders. The most notable incursion into Florida occurred during Andrew Jackson's campaign against the Seminole Indians in 1817–18 (First Seminole War), which included attacks on Spanish outposts he accused of aiding the Indians. These actions, and the often bellicose rhetoric from north of the border, convinced many Spanish officials that the United States would eventually annex Florida by force.

While Jackson's troops were in action in Florida, President James Monroe directed his secretary of state, John Quincy Adams, to renew American offers to purchase Florida. By this time, Spain, beset by financial problems and fearing that it could not defend Florida against an increasingly likely American invasion, was becoming more amenable to negotiation. Spain first sought British aid, but when that was not forthcoming, it decided that it was better to sell Florida than to run the risk of losing it with no gain. The result was the Adams-Onís Treaty signed on February 22, 1819, by Adams and the Spanish foreign minister, Don Luis de Onís Gonzalez Lopez y Vara. Within the United States, the treaty was considered a great triumph, although some politicians from the western states, led by Henry Clay, believed that government officials should have held out for the inclusion of Texas as part of the accord.