Both wars sucked up several major powers into the conflict. In addition, in both wars the central conflict did not involve the USA, but the USA was sucked into it for ideological and business interests. the war ended in a a peace treaty, and there was no decisive victor, but it appeared the USA lost the war politically because of the unpopularity of both wars.
The original purpose of the convention was to search for ways to improve the Articles of Confederation. However the Framers changed the purpose to writing a new constitution because they thought the problems were too serious to try correct.
