Jefferson advocated strict adherence to the U.S. Constitution and there were no provisions within the Constitution to permit the U.S.' purchase of new territory. However, because of wide popular support for the purchase of the new territory as well as the value the territory would bring to the newly formed United States Jefferson decided to forgo the legalistic view of the Constitution and supported the purchase of the territory.
Jefferson was initially concerned about the Louisiana Purchase due to constitutional limitations on the President's authority to acquire new land. However, recognizing the strategic benefits of the purchase for national security and expansion, he reasoned these doubts away and proceeded with the acquisition. Ultimately, the deal significantly expanded the United States and is one of Jefferson's key achievements.
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