Answer:
France
Explanation:
The US purchased a territory of around 830 000 square miles of land from France in December 1803. The price was 80 French marks equivalents to 15 million dollars of that time.
The vast domains of Louisana included the fifteen current states of Arkansas, Missouri, Iowa, Oklahoma, Kansas, and Nebraska as well as portions of large territories of today like North Dakota and South Dakota; the area of Montana, Wyoming, and Colorado.
Lousiana lands were originally colonized by the French during the 18th century reaching north into Canada , and the acquisition of land came in a time when the Union was expanding eastwards.
With the purchase, the exploration of Louisiana connected the territories shown in the image below, in a time when the East and the West were still distant.
The Louisiana terriory became years later in 1812 part of the Union.
