The United States Senate ratified the Louisiana Purchase Treaty by a vote of 24-7 on this day in 1803. The vast region encompassed more than 800,000 square miles of territory and comprised present-day Arkansas, Missouri, Iowa, Minnesota west of the Mississippi River, North Dakota, South Dakota, Nebraska, Oklahoma, nearly all of Kansas, the portions of Montana, Wyoming, and Colorado east of the Rocky Mountains, and Louisiana west of the Mississippi River as well as the city of New Orleans. At the time of purchase, Thomas Jefferson was concerned about the constitutionality of making a land acquisition without adding a covering amendment to the U.S. Constitution. The law of the land, however, did give the president treaty-making power, and the Louisiana Purchase was ratified into law as a treaty by the U.S. Senate. The Louisiana Purchase stands as the largest area of territory ever added to the U.S. at one time.