A chief aim of the Constitution as drafted by the Convention was to create a government with enough power to act on a national level, but without so much power that fundamental rights would be at risk. One way that this was accomplished was to separate the power of government into three branches, and then to include checks and balances on those powers to assure that no one branch of government gained supremacy. This concern arose largely out of the experience that the delegates had with the King of England and his powerful Parliament. The powers of each branch are enumerated in the Constitution, with powers not assigned to them reserved to the states.
Much of the debate, which was conducted in secret to ensure that delegates spoke their minds, focused on the form that the new legislature would take. Two plans competed to become the new government: the Virginia Plan, which apportioned representation based on the population of each state, and the New Jersey plan, which gave each state an equal vote in Congress. The Virginia Plan was supported by the larger states, and the New Jersey plan preferred by the smaller. In the end, they settled on the Great Compromise (sometimes called the Connecticut Compromise), in which the House of Representatives would represent the people as apportioned by population; the Senate would represent the states apportioned equally; and the President would be elected by the Electoral College. The plan also called for an independent judiciary.
The founders also took pains to establish the relationship between the states. States are required to give "full faith and credit" to the laws, records, contracts, and judicial proceedings of the other states, although Congress may regulate the manner in which the states share records, and define the scope of this clause. States are barred from discriminating against citizens of other states in any way, and cannot enact tariffs against one another. States must also extradite those accused of crimes to other states for trial.
The founders also specified a process by which the Constitution may be amended, and since its ratification, the Constitution has been amended 27 times. In order to prevent arbitrary changes, the process for making amendments is quite onerous. An amendment may be proposed by a two-thirds vote of both Houses of Congress, or, if two-thirds of the states request one, by a convention called for that purpose. The amendment must then be ratified by three-fourths of the state legislatures, or three-fourths of conventions called in each state for ratification. In modern times, amendments have traditionally specified a timeframe in which this must be accomplished, usually a period of several years. Additionally, the Constitution specifies that no amendment can deny a state equal representation in the Senate without that state's consent.
With the details and language of the Constitution decided, the Convention got down to the work of actually setting the Constitution to paper. It is written in the hand of a delegate from Pennsylvania, Gouverneur Morris, whose job allowed him some reign over the actual punctuation of a few clauses in the Constitution. He is also credited with the famous preamble, quoted at the top of this page. On September 17, 1787, 39 of the 55 delegates signed the new document, with many of those who refused to sign objecting to the lack of a bill of rights. At least one delegate refused to sign because the Constitution codified and protected slavery and the slave trade.