The Adams-Onis Treaty of 1819

Instructor: Christina Boggs

Chrissy has taught secondary English and history and writes online curriculum. She has an M.S.Ed. in Social Studies Education.

Before Florida was the home to Mickey Mouse and Walt Disney World, it was a colony owned by the Spanish. This lesson explains how the United States acquired Florida through the Adams-Onis Treaty of 1819.

The Florida Colonies

How much do you know about the state of Florida? Even if you've never been there, you're probably familiar with some of its major attractions, like Walt Disney World and Universal Studios. You may also be familiar with some of the dangerous wildlife, like alligators and venomous snakes. But did you know that before Florida was the Sunshine State, it was actually two different colonies that were owned by Spain?

The Spanish controlled the Florida colonies from the 1500s up until 1763. After the Treaty of Paris ended the Seven Years' War, Great Britain took ownership of Florida. The warm and sunny colonies changed hands once more after the American Revolution came to an end. The Peace of Paris in 1783 returned Florida back to Spain. Unfortunately for Spain, it didn't hold onto the warm paradise for long!

The United States and the Florida Colonies

After the American Revolution came to an end, many American colonists moved into the colonies of West Florida and East Florida. In 1810, a number of these settlers decided to stage an uprising against Spanish rule. At the same time, Spain was in the middle of a war with Napoleon's France. The U.S. government realized Spain's predicament and decided to take advantage of the situation. President James Madison formally declared West Florida a territory of the United States. He justified this action by claiming that West Florida was actually a part of the Louisiana Purchase made in 1803. Whether this was true or not didn't really matter. Spain's resources were spread too thin and there was little chance they'd go to war with the U.S. over the colony.

Negotiations Begin

In 1815, Spain sent Don Luis de Onis, the Spanish minister to the United States, to sort out territorial claims over Florida. At the time, James Madison was president and James Monroe was state secretary. After nearly three years, James Monroe had become the president, and the new Secretary of State John Quincy Adams took over the negotiations.

Don Luis de Onis
Luis de Onis

The talks almost came to an end thanks to General Andrew Jackson (a future U.S. president). Florida was not only the home to American and Spanish colonists, it was also the home to the Seminole Indians. The Seminoles were notorious for leading bloody raids against the people living in Georgia. Jackson led American troops into Spanish Florida to deal with the Seminoles. During his excursion, Jackson managed to take over two Spanish forts.

The Adams-Onis Treaty of 1819

While President Monroe was worried by Jackson's actions, Secretary of State Adams used them to the United States' advantage. Adams gave Onis an ultimatum: Either Spain kept East Florida under control (including the Seminoles), or the United States would take over. Ultimately, Spain agreed to the terms of the Adams-Onis Treaty (also called the Transcontinental Treaty):

  • The United States officially received both West Florida and East Florida.
  • Spain gave up all claims to the Oregon Territory (located in the Pacific Northwest).
  • The United States agreed to pay $5 million in damages for the uprisings in 1810.
  • Spain received official recognition as the sovereign of Texas.

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