Answer:
The answer to the question: Which European power claimed the largest territory in North America would be: Great Britain.
Step-by-step explanation:
It must be remembered that North America was claimed by four different European countries: Spain, Sweden, France and Britain. Each of these had a good portion of land, but the one European country that had the most land claimed, and remained owner of it until the American Revolution, was Great Britain. Although Spain had a good chunck with its ownership for a while of Florida, and France with Louisiana and the territories of Canada, it was Great Britain who maintained ownership of all of the lands east of the Mississippi river, with the 13 colonies. Later on they acquired Florida from Spain and also territories from Canada, further expanding.