Before 1789, the U.S. had been ruled by the Articles of
Confederation (1781) in fear of govt. abusing power (like British rule).
In 1787, it was obvious that they needed a perfect Union and so, while
protecting the independence of states, the Articles of Confederation
didn't describe the powers of a federal chief executive nor a judicial
system. The creation of our Constitution and present form of government
was informed by these and other considerations that arose during the
years of the Confederation.