Final answer:
The United States sent General Andrew Jackson into Florida in 1817 to address security concerns and quell Indian raids along the southern border. This eventually led to the acquisition of Florida through the Adams-Onís Treaty of 1819.
Step-by-step explanation:
In 1817, the United States sent General Andrew Jackson into Florida to quell the Indian raids and address security concerns along the southern border.
These raids were carried out by Creek and Seminole militants who sought refuge in Florida after attacking American settlers in Georgia.
The invasion of Florida led to further negotiations with Spain, eventually resulting in the Adams-Onís Treaty of 1819, through which the United States acquired Florida.