Final answer:
The untrue statement is that Andrew Jackson's incursion into Florida had diplomatic approval from Spain; Spain did not consent to Jackson's actions which led to tension and the eventual Adams-Onís Treaty.
Step-by-step explanation:
The statement regarding Andrew Jackson's incursion into Florida that is not true is that it had diplomatic approval from Spain. In fact, General Andrew Jackson's actions in Florida preceded any diplomatic approval and were a point of tension between the Spanish government and the United States. Jackson's foray into Florida was a unilateral military action where he pursued Creek and Seminole fighters into Spanish territory without Spain's consent. This eventually led to the negotiated Adams-Onís Treaty of 1819, where Spain ceded Florida to the United States. It is also worth mentioning that Jackson did have alliances with Native American tribes such as the Cherokees and Creeks who aided in the military action, and he used significant military force during the incursion.