I would say there were more than two things that motivated the Founding Fathers to write the Constitution. The motivations of these people were many. But in terms of broad motives, I think we can pin down two:
To create a workable government. In the eyes of many Founding Fathers, the Articles of Confederation did not give enough power to the central government. The Articles government did not work. They drafted a new document to fix its problems. They did things like allowing Congress to tax, creating an executive and judicial branch to enforce Congress’ laws, and establishing for sure that the Federal Government had supremacy over the states.
To create a limited government. Nevertheless, the Founding Fathers (nearly all of whom would be considered libertarians today) did not want the Federal Government to have broad authority over our lives. Their federalist beliefs convinced them that broad authority should rest in the hands of the states, or better yet, the individual. They accomplished this by giving all legislative power to Congress and then by assigning specific powers to Congress. The enumerated powers are intended to limit Congress’ actions and prevent it from assuming it has power in any area.
France returned to the North American stage in 1778 to support American colonists against Great Britain in the Revolutionary War. For France, the military defeat and the financial burden of the Seven Years' War weakened the monarchy and eventually contributed to the advent of the French Revolution in 1789.
