Final answer:
The French territory in North America extended from the Mississippi River to the Rocky Mountains. France's colonization left a lasting cultural impact, especially in Quebec and along the Mississippi. The Louisiana Purchase by the U.S. significantly enlarged American territory.
Step-by-step explanation:
The French territory in North America stretched from the Mississippi River to the Rocky Mountains. France was the first European country to colonize eastern Canada, the St. Lawrence River Valley, and the Ohio and Mississippi River valleys, extending south to the Gulf of Mexico. Despite the eventual cession of their territory to Great Britain following the Treaty of Paris in 1763, French cultural influence remained strong. The evidence of French colonization can be seen in place names and land-use patterns, particularly in Quebec and regions along the Mississippi River.
Additionally, the Louisiana Purchase of 1803, which was a sale by Napoleon of French North American territory to the United States, notably doubled the size of the U.S. by including land from the Mississippi River to the Rocky Mountains. This vast expanse of new American territory would significantly shape the future development and expansion of the United States.