The most contentious disputes revolved around composition and election of the upper legislative house in the future bicameral Congress, to be known as the Senate, how "proportional representation" was to be defined (whether to include slaves or other property), whether to divide the executive power between three persons or invest the power into a single chief executive to be called the President, how to elect the President, how long his term was to be and whether he could run for reelection, what offenses should be impeachable, the nature of a fugitive slave clause, whether to allow the abolition of the slave trade, and whether judges should be chosen by the legislature or executive. Most of the time during the Convention was spent on deciding these issues, while the powers of legislature, executive, and judiciary were not heavily disputed. Once the Convention began, the delegates first agreed on the principles of the Convention, then they agreed on Madison's proposed Virginia Plan and began to modify it. A Committee of Detail, assembled during the July 4th recess, eventually produced a rough draft of the constitution. Most of the rough draft remained in place, and can be found in the final version of the constitution. After the final issues were resolved, the Committee on Style produced the final version, and it was voted on by the delegates, inscribed on parchment with engraving for printing and sent to the states and their legislatures.
Before the Constitution was drafted, the nearly 4 million inhabitants of the 13 newly independent states were governed under the Articles of Confederation and Perpetual Union, created by the Second Continental Congress. It soon became evident to nearly all that the chronically underfunded Confederation government, as originally organized, was inadequate for managing the various conflicts that arose among the states.:4–5:14–16 As the Articles of Confederation could only be amended by unanimous vote of the states, any state had effective veto power over any proposed change. In addition, the Articles gave the weak federal government no taxing power: it was wholly dependent on the states for its money, and had no power to force delinquent states to pay.
Once the immediate task of winning the American Revolutionary War of 1775 to 1783 had passed, the states began to look to their own interests, and disputes arose. These included a dispute between Maryland and Virginia over the Potomac River and opposition to Rhode Island's imposing taxes on all traffic passing through it on the post road. James Madison suggested that state governments should appoint commissioners "to take into consideration the trade of the United States; to examine the relative situation and trade of said states; to consider how far a uniform system in their commercial regulations may be necessary to their common interests and permanent harmony".:92
Another impetus for the convention was Shays' Rebellion of 1786-1787. A political conflict between Boston merchants and rural farmers over issues including tax debts had broken out into an open rebellion. This rebellion was led by a former Revolutionary War captain, Daniel Shays, a small farmer with tax debts, who had never received payment for his service in the Continental Army. The rebellion took months for Massachusetts to put down completely, and some desired a federal army that would be able to put down such insurrections.
In September 1786, at the Annapolis Convention, delegates from five states called for a Constitutional Convention in order to discuss possible improvements to the Articles of Confederation. The subsequent Constitutional Convention took place in Philadelphia, convening in the Old Pennsylvania State House (then becoming known as Independence Hall) on May 14, 1787. Rhode Island, fearing that the Convention would work to its disadvantage, boycotted the Convention and, when the Constitution was put to the states during the next year of controversial debates, initially refused to ratify it, waiting until May 1790 to become the thirteenth, a year after the new federal government commenced.