The Peninsula Cooter (Pseudemys peninsularis) is (originally) only found in Florida.
In some countries in Europe, they have been introduced through the pet trade.
The flatter turtles are Peninsula Cooters.
The bulkier one in the middle, with more yellow on the throat, is a Yellow-bellied Slider (Trachemys scripta scripta).

Hamburg, Germany, 26 August 2014