What did France do to gain control over Florida?

France never gained control over Florida. However, France did briefly control the area that would become Florida.

In the 1500s, France founded several settlements in North America including in Florida. In 1562, the French started a settlement in what is now Jacksonville, Florida. The settlement lasted for about 20 years. They attempted to establish a colony in Florida around the St. Johns River. Their efforts were eventually thwarted by the Spanish, who claimed Florida as part of their New Spain territory.