Actually the southern half of Florida does have some Crocodiles.

http://en.wikipedia.org/wiki/American_crocodile

Ran into one when I was a kid and well I have a very firm imprint that they in fact do live there.

Well, we do have the American Crocodile[0] whose ranges includes southern Florida. Florida also has Caimans[1], but those are invasive.

[0] - http://en.wikipedia.org/wiki/American_crocodile

[1] - http://myfwc.com/wildlifehabitats/managed/american-crocodile...

The American crocodile is mostly found in Central America and the Caribbean, but also exists in the Everglades. I'm pretty sure it is an endangered species.