It was apparent that the delegates at Philadelphia that the national government had to be strengthened and given enough authority to tax and regulate the economy. But they faced a dilemma: the Americans had just fought a revolution against a powerful central government that was, in their eyes, taxing them excessively. Centralised power brought with it the possibility of tyranny, military dictatorship and the trampling of individual liberties. The delegates’ response was to craft a stronger national government but divide it into three branch. Each branch would have considerable power, however the constitutional document would contain an intricate system of ‘checks and balances’. The theory was that each branch would ‘push and pull’ against the others and that they would therefore exist in a state of equilibrium; no single branch could assume enough power to become tyrannical or dictatorial.
The suggestion of competing branches of government was not a new one. It was put forward in Philadelphia by James Madison – but the English political system itself was based on separate and competing branches (a monarch, a parliament of two houses and an independent judiciary). The Enlightenment philosopher Montesquieu wrote extensively about ‘mixed governments’ and separation of powers in his 1734 work The Spirit of the Laws. What Madison proposed was a republican refinement of this idea rather than a radical new innovation. Under the constitution, the three branches (see picture) would be:
The executive branch, led by a popularly elected president. He would act as head of state, appoint a cabinet (made up of secretaries), enforce laws, act as commander-in-chief of the military and be responsible for the day to day administration of the nation.
The legislative branch, a representative assembly in the form of the Congress. Its role was to pass laws and to control and regulate tax, trade, finance and the issue of currency.
The judicial branch would be created, led by the Supreme Court, which would act as the highest court in the land. The Supreme Court would interpret the Constitution and decide whether laws, regulations and executive orders were valid or ‘legal’ according to the Constitution.
A historian’s view:
“Not all Americans were willing to publicly admit that the models they should seek to follow were those of the country whose rule they had thrown off… But the members of the  Convention continued to argue about the details of the proposed new constitution largely by analogy with [the political system of] Britain. Save for the small republics of the Netherlands and Switzerland, there was nowhere else to look.”
The checks and balances contained in the Constitution are too numerous to include here, but some of them are well known. The president is reliant on Congress for appropriation, so he must routinely send requests for funding to the legislature. The president appoints members of the Supreme Court and secretaries in his Cabinet, but Congress must approve these appointments. The president can veto (suspend) any bill that is passed by Congress but this veto can be overturned with a two-thirds majority vote in Congress. The president commands the military but only Congress can declare war. The president can be impeached (i.e. put on trial) by the Senate, the upper house of the Congress, and dismissed.
Another issue that plagued the delegates was how smaller states can be protected from larger states. The smaller less wealthy states (Rhode Island, for example) were concerned about being overridden and politically dominated by states like Virginia, Massachusetts and New York. At one stage in the Convention, these divisions created a deadlock in proceedings. The answer came in the form of a proposal called the ‘Great Compromise’, which came from the Connecticut delegates, and was based on a Congress that would be bicameral (i.e. would have two houses):
The lower house of Congress (the House of Representatives) would be elected on the basis of population, that is, seats based on the number of people in each state
The upper-house of Congress (the Senate) would contain two representatives from each state, regardless of its size, wealth or population
Each house has an equal role in the passing of legislation; bills must pass both houses to be enacted
Each house has certain authorities or tasks not possessed by the other, e.g. the House of Representatives can only raise revenue bills, while the Senate alone must confirm all important public appointments such as Supreme Court judges, Cabinet members and ambassadors
This system should look familiar to students of Politics and Legal Studies because the Australian system is modelled on it. In the Australian federal system, the Senate acts as a ‘states house’, a check on the popularly-elected House of Representatives that theoretically protects the interests of the states. This compromise proposal broke the July deadlock in the Convention and allowed constitutional development to continue. In debating the process by which the House of Representatives would be elected, a less appealing compromise was passed: to accommodate the southern states who relied on slavery, it was agreed that three-fifths of a state’s slave population should be counted in determining the number of seats that state should have in the House (even though the slaves were not permitted to vote, their numbers would be ‘counted’ for the purpose of elections!) Slaves were also counted as property for the purposes of calculating tax, and trading of slaves was constitutionally protected until 1808. So for all its advantages and clever initiatives, the Constitution also institutionalised slavery in the new nation (a factor that would contribute to future division and eventually, in 1861, to the Civil War).