What was the legal basis for the us to purchase the louisiana territory?

The legal basis for the United States purchase of the Louisiana Territory was the

 1. power granted to the President to make treaties 

 2. President’s power as Commander in Chief 

 3. authority of Congress to declare war 

 4. Senate’s duty to approve the appointment of ambassadors

The main reason for the failure of the Treaty of Versailles was because of the restrictions and debt that Germany was forced to incur as a result of the war. With land taken away and an economy and country in ruin, the seeds were planted for the rise of a nationalist like Hitler and the beginnings of WWII.