When the Spanish were slow in reaching a diplomatic solution to the issue of Florida, General Andrew Jackson took matters into his own hands and invaded Florida in order to attack the Seminole Indians. In the process, he captured Alexander Arbuthnot, a Scottish trader who had given the Indians a warning about the impending arrival of Jackson. Later, at the village of Chief Bowlegs on the Suwanee River, he captured an English trader, Robert Ambrister, who had been involved in planning an Indian uprising.
The two men were given courts-martial at St Mark's, and after conviction, Arbuthnot was hanged and Ambrister was shot on April 29, 1818. The British government took no action with respect to their countrymen, but Spain loudly denounced the invasion and the executions. Secretary of State John Quincy Adams publicly defended Jackson's actions.
Unable to gather support against the United States for this or any other incident, Spain at last signed the Adams-Onis Treaty in February, 1819, ceding all of East Florida to the United States.