Nice quiz, just a slight correction: Canada should be on here also. Your source doesn’t include it because it wasn’t a colony, but the Louisiana Purchase gave land to the US that was given to Britain in the Treaty of 1818. From the treaty’s Wikipedia page: “the United States' only permanent significant cession of North American territory to a foreign power” The years would be from 1803-1818.
List the present-day countries some or all of whose land was once (but is no longer) under possession of the United States.