The 18th-century statesmen who met in Philadelphia were adherents of Montesquieu's concept of the balance of power in politics. This principle was supported by colonial experience and strengthened by the writings of John Locke, with which most of the delegates were familiar. These influences led to the conviction that three equal and coordinate branches of government should be established. Legislative, executive and judicial powers were to be so harmoniously balanced that no one could ever gain control. The delegates agreed that the legislative branch, like the colonial legislatures and the British Parliament, should consist of two houses.  

On these points there was unanimity within the assembly. But sharp differences arose as to the method of achieving them. Representatives of the small states -- New Jersey, for instance -- objected to changes that would reduce their influence in the national government by basing representation upon population rather than upon statehood, as was the case under the Articles of Confederation.  

On the other hand, representatives of large states, like Virginia, argued for proportionate representation. This debate threatened to go on endlessly until Roger Sherman came forward with arguments for representation in proportion to the population of the states in one house of Congress, the House of Representatives, and equal representation in the other, the Senate.  

The alignment of large against small states then dissolved. But almost every succeeding question raised new problems, to be resolved only by new compromises. Northerners wanted slaves counted when determining each state's tax share, but not in determining the number of seats a state would have in the House of Representatives. According to a compromise reached with little dissent, the House of Representatives would be apportioned according to the number of free inhabitants plus three-fifths of the slaves.  

Certain members, such as Sherman and Elbridge Gerry, still smarting from the Shays Rebellion, feared that the mass of people lacked sufficient wisdom to govern themselves and thus wished no branch of the federal government to be elected directly by the people. Others thought the national government should be given as broad a popular base as possible. Some delegates wished to exclude the growing West from the opportunity of statehood; others championed the equality principle established in the Northwest Ordinance of 1787.  

There was no serious difference on such national economic questions as paper money, laws concerning contract obligations or the role of women, who were excluded from politics. But there was a need for balancing sectional economic interests; for settling arguments as to the powers, term and selection of the chief executive; and for solving problems involving the tenure of judges and the kind of courts to be established.  

Laboring through a hot Philadelphia summer, the Convention finally achieved a draft incorporating in a brief document the organization of the most complex government yet devised -- a government supreme within a clearly defined and limited sphere. In conferring powers, the Convention gave the federal government full power to levy taxes, borrow money, establish uniform duties and excise taxes, coin money, fix weights and measures, grant patents and copyrights, set up post offices, and build post roads. The national government also had the power to raise and maintain an army and navy, and to regulate interstate commerce. It was given the management of Indian affairs, foreign policy and war. It could pass laws for naturalizing foreigners and controlling public lands, and it could admit new states on a basis of absolute equality with the old. The power to pass all necessary and proper laws for executing these clearly defined powers rendered the federal government able to meet the needs of later generations and of a greatly expanded body politic.  

The principle of separation of powers had already been given a fair trial in most state constitutions and had proved sound. Accordingly, the Convention set up a governmental system with separate legislative, executive and judiciary branches -- each checked by the others. Thus congressional enactments were not to become law until approved by the president. And the president was to submit the most important of his appointments and all his treaties to the Senate for confirmation. The president, in turn, could be impeached and removed by Congress. The judiciary was to hear all cases arising under federal laws and the Constitution; in effect, the courts were empowered to interpret both the fundamental and the statute law. But members of the judiciary, appointed by the president and confirmed by the Senate, could also be impeached by Congress.  

To protect the Constitution from hasty alteration, Article V stipulated that amendments to the Constitution be proposed either by two-thirds of both houses of Congress or by two-thirds of the states, meeting in convention. The proposals were to be ratified by one of two methods: either by the legislatures of three-fourths of the states, or by convention in three-fourths of the states, with the Congress proposing the method to be used.  

Finally, the Convention faced the most important problem of all: how should the powers given to the new government be enforced? Under the Articles of Confederation, the national government had possessed -- on paper -- significant powers, which, in practice, had come to naught, for the states paid no attention to them. What was to save the new government from the same fate?  

At the outset, most delegates furnished a single answer -- the use of force. But it was quickly seen that the application of force upon the states would destroy the Union. The decision was that the government should not act upon the states but upon the people within the states, and should legislate for and upon all the individual residents of the country. As the keystone of the Constitution, the Convention adopted two brief but highly significant statements:  

Congress shall have power...to make all laws which shall be necessary and proper for carrying into execution the...powers vested by this Constitution in the Government of the United States....(Article I, Section 7)  

This Constitution and the laws of the United States, which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every State shall be bound thereby, any thing in the Constitution or laws of any State to the contrary notwithstanding. (Article VI)  

Thus the laws of the United States became enforceable in its own national courts, through its own judges and marshals, as well as in the state courts through the state judges and state law officers.  

Debate continues to this day about the motives of those who wrote the Constitution. In 1913 Charles Beard, in An Economic Interpretation of the Constitution, argued that the Founding Fathers stood to gain economic advantages from the stability imposed by a powerful and authoritative national government because they held large amounts of depreciated government securities. However, James Madison, principal drafter of the constitution, held no bonds, while some opponents of the Constitution held large amounts of bonds and securities. Economic interests influenced the course of the debate, but so did state, sectional and ideological interests. Equally important was the idealism of the framers. Products of the Enlightenment, the Founding Fathers designed a government that, they believed, would promote individual liberty and public virtue. The ideals embodied in the U.S. Constitution are an essential element of the American national identity.