In early 1818, an army of Tennessee and Kentucky volunteers, Georgia militiamen, and U.S. soldiers under the command of Andrew Jackson crossed into Spanish Florida. They fought a few skirmishes with Seminole and Creek warriors, burned several villages, and captured two British nationals. Both were executed after a makeshift court martial. This set off what one Congressman called a “Great National Question,” or rather several. Was the United States bound by the so-called “law of nations,” the forerunner to international law? Or were the American people victims of that law along with the allegedly “lawless” peoples of Florida? This lecture offers a close look at both the invasion and the debate that followed, along with some broader thoughts on early American ideas about law, natural rights, and the morality of vengeance.