The first Europeans to settle in St. Augustine, Florida were the Spanish. St. Augustine, Florida was founded in 1565 by Spanish admiral Pedro Menéndez de Avilés. The admiral named it St. Augustine because his ships bearing settlers, soldiers, and supplies from Spain first sighted land on August 28th, the feast day of Saint Augustine.
Florida in Spanish means "full of flowers" Yes, well as that is true, that is not what the question was asking. The answer is that without Spanish cultures and heritage, Florida would not be anything like it is today. So many people in Florida speak Spanish and there are so many different types of Spanish items that I bet you use everyday that we wouldn't have without the Spanish.
According to page 299 of Section 1 of the 7th grade Social Studies Text Book; "United States History", the proper answer for this question would be that the Adams-Onís Treaty is the solution to conflicts between the United States and Spanish Florida. The treaty was signed to make peace with each other, so they can settle all borders of disputes between the two.