D. New York, Massachusetts, Vermont
With the Louisiana Purchase of 1803, the U.S. acquired territory of approximately 828,000,000 square, almost half of what the U.S. is today.
The states that formed from that territory were the following: Arkansas, Missouri, Iowa, Oklahoma, Kansas, and Nebraska, and some sections of the following: Minnesota, North Dakota, South Dakota, New Mexico, Texas, Montana, Wyoming, Colorado, and Louisiana. And portions of the Canadian provinces of Alberta and Saskatchewan. The states of New York, Massachusetts, Vermont were not formed from this territory.