The constitutionality of the Louisiana Purchase

James Madison and I talked seriously about the constitutionality of the Louisiana Purchase because I was deeply worried that the Constitution did not give the government the clear power to buy new land. I believed we needed to follow the Constitution strictly, so I actually started writing an amendment to make the deal legal.

However, Madison (who is widely known as the "Father of the Constitution") and my Treasury Secretary, Albert Gallatin, strongly disagreed with waiting.

Despite being the primary architect of the Constitution itself, Madison argued that we could legally buy the land using the document's existing rules for making treaties. He also warned me that if we took too long trying to pass an amendment, Napoleon might change his mind and cancel the deal. In the end, the creator of the Constitution convinced me; I dropped the idea of an amendment and sent the treaty straight to the Senate so we wouldn't lose this great opportunity for our country.

And with that, we doubled the size of the United States overnight (i.e., five days in Congress).