Principles of the American System of Government.

The foundation of American Governance is rooted in the Enlightenment Ideals of the Founding Fathers as expressed in the Declaration of Independence and the Constitution of the United States.
These Ideals are summed up in The Declaration of Independence when it says:

"We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the Pursuit of Happiness--That to secure these Rights, Governments are instituted among Men, deriving their just Powers from the Consent of the Governed."

In this one sentence we see the principles of Popular Sovereignty,  Republicanism, and Individual Rights.That Governments exist to serve the people of the state, they gain power only through the consent of those they hope to govern.  To protect these basic ideals the founding fathers instituted other ideals including federalism, separation of powers, checks and balances, and limited government through the US Constitution.

Federalism is the ideal that the National Government should have limited powers and should share responsibility for governing with the state and local governments.  By limiting the power of the National government the founding fathers hoped to keep more of the decisions at the level where the people most effected had the most influence.

At the National level the government is separated into 3 equal branches.  Each branch is responsible for a different function of government. By separating the power of the government in to 3 branches the founding fathers hoped to keep any one group from gaining too much power and acting outside the will of the people.  To that end the 3 branches also serve as a check on each.  The Legislative Branch (Congress) to write the laws (their Power) and control the purse (Allocating Money, check on the Executive Branch) and approve the appointment of Judges (Check on the Judicial Branch).  The Executive Branch (The President) approves and enforces the legislation and rules set out by the Legislative Branch (Check on the Legislative) , spends the money allocated by the legislative branch and appoints Judges (Check on the Judicial Branch).  The Third branch is the Judicial Branch consisting of the Supreme Court and lower federal courts.  The job of the Judicial Branch is to rule the enforcement of the law (Check on the Executive) as well as the constitutionality of the law (Check on the Legislative).

The last Ideal is one of limited government.  The Government ONLY had the power specifically given to it.  The Government is supposed to act only within the guidelines laid out by the Constitution.