The greatest territorial acquisition that added the most number of states to the nation, excluding the original United States, was the Louisiana Purchase. The Louisiana Purchase took place in 1803 when the United States bought approximately 827,000 square miles of land from France for $15 million. This acquisition doubled the size of the country at the time and eventually led to the creation of 15 new states, including Arkansas, Missouri, Iowa, Oklahoma, Kansas, Nebraska, Minnesota, Louisiana, South Dakota, North Dakota, Montana, Wyoming, Colorado, Idaho, and parts of New Mexico.
