Answer:
Domestic Tranquility
One of the concerns of the Framers was that the government prior to that under the Constitution was unable, by force or persuasion, to quell rebellion or quarrels amongst the states. The government watched in horror as Shay's Rebellion transpired just before the Convention, and some states had very nearly gone to war with each other over territory (such as between Pennsylvania and Connecticut over Wilkes-Barre). One of the main goals of the Convention, then, was to ensure the federal government had powers to squash rebellion and to smooth tensions between states.