Final answer:
The Louisiana Purchase posed a constitutional dilemma for President Jefferson because the acquisition of new territory through purchase was not expressly granted in the Constitution, conflicting with his strict interpretation principles.
Step-by-step explanation:
The Louisiana Purchase created a constitutional conundrum for President Jefferson because technically, there was nothing in the Constitution that granted the President the power to acquire new land through purchase. Jefferson, a proponent of strict constitutional interpretation, found it challenging to reconcile this acquisition with his philosophy of government. However, his vision of an agrarian society and the strategic value of controlling the Mississippi River and New Orleans were too significant to pass up. Jefferson assigned Robert Livingston and James Monroe to complete the negotiation, and they secured the deal with Napoleon, who was motivated to sell due to his own political and economic circumstances. Ultimately, Jefferson proceeded with the purchase, although it troubled him, and for $15 million, the United States territory was effectively doubled, paving the way for westward expansion.