Habeas Corpus is a British legal tradition that has passed into American law. It essentially states that the government cannot detain a citizen for a lengthy period of time without a trial. It ensures no illegal detention, and that every accused individual will be given the opportunity to go to court to be acquitted of any wrongdoing.

The Magna Carta was a document signed between King John II and the English nobility in the thirteenth century. It was intended to prevent the King from abusing his power and aimed to protect certain rights of the nobility. It is often considered the beginning of English democracy and thus American democracy.

The Magna Carta was signed in 1215 between English nobles and King John II. The Declaration of Independence was signed in 1776, and the Articles of Confederation were signed into practice in 1781.

The Magna Carta (1215) was the first legal attempt to check the power of the English monarchy and to guarantee certain rights for some of the population. Seen as the founding moment of English democracy, it is worth considering that it only protected the nobles and other aristocrats from the abuses of the monarchy, and it would be a few hundred years before any true democracy began to take shape in England. Still, it is a seminal moment in the progression from autocratic monarchy to representative democracy in the English-speaking world.

The pilgrims who arrived in Massachusetts from Europe were fleeing religious persecution in England under King James I. They signed the Mayflower Compact which essentially stated they were an autonomous and self-governing people.

The opening text of the Declaration of Independence reads: 

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, that whenever any Form of Government becomes destructive of these Ends, it is the Right of the People to alter or abolish it, and to institute a new Government...

The Declaration of Independence was inspired by the burgeoning liberal tradition which held that it was nobody's natural right to rule over a people regardless of their wishes. Political legitimacy, instead of being based upon divine right or noble birth, is a matter of self-determination among those who consent to being governed. 

The Declaration of Independence was written by Thomas Jefferson. He famously adapted John Locke’s views that all men have the right to "life, liberty, and property" to "life, liberty, and the pursuit of happiness."

The Federalist Papers were written by James Madison, Alexander Hamilton, and John Jay in 1790 and 1791 as a series of newspaper editorials. The Federalist Papers were a series of essays written to support the ratification of the Constitution and garner support for a strong and centralized national government.

In the American system of federalism, the federal government makes the supreme law of the nation that all the states must follow; however, to prevent a tyranny of the national government (something greatly feared by the states and the Constitutional framers) the Tenth Amendment of the Constitution declares that all powers that are not explicitly reserved for the federal government fall to the state governments.

For many Americans the freedom to practice their religion was one of the reasons why they moved to the colonies in the first place. Many colonists had been persecuted for their religion in Europe, and so when it came time to establish their own government, freedom of religion was considered extremely important. The Establishment Clause in the Constitution prohibits the government from establishing a state religion.