Final answer:
Andrew Jackson led the expedition and almost caused an international crisis with Spain, but it ultimately led to the United States negotiating to purchase Florida from Spain.
Step-by-step explanation:
The person who led the expedition to Florida, nearly causing an international crisis with Spain, was Andrew Jackson. In the early 1800s, Jackson conducted several military campaigns against Native American tribes in Florida. During one of these campaigns, he seized two Spanish forts, leading to tensions between the United States and Spain. Ultimately, this episode resulted in negotiations between the two countries, leading to the United States purchasing Florida from Spain in the Adams-OnĂs Treaty of 1819.
Learn more about Andrew Jackson's expedition to Florida