A constitution is a set of rules that a government must follow in order to govern it's people. In the United States the rules for government includes 3 separate branches of government and 7 principles. The most integral part of the social contract is the Constitution, in effective government it defends the rights to sovereignty, due process, and individual rights. In the United States Constitution and others that it inspired, the framers included an amendment process in order to make it what's known as a "living document," or a document that changes over time. The first ten amendments to the Constitution
The Constitution starts with a Preamble, followed by 7 articles/rules for government (including the 3 branches), and ends with the Bill of Rights and other amendments that have been made over time. The vision of what American government should be came from a time of Revolution, and was written into the current US Constituion at what was known as the Constitutional Convention after the failure of America's first constitution: the Articles of Confederation, which failed to provide a united government or protect individual rights.
With the signing of the Treaty of Paris in 1783, the United States was recognized by Great Britain and the world as a free and independent country, and from here the trouble only became more complex. Once the larger enemy - the British - were deposed the question would shift entirely. How would this New Nation founded on Enlightenment ideals govern itself? It's a question that still affects us today, because with only a short list of amendments called the Bill of Rights, the same Constitution governs our nation today. These precedents determined how the Constitution would be interpreted, and how the words "all men are created equal" from the Declaration of Independence would be put to the test and recorded into the Supreme Law of the Land.
In unit 1 you learned about European Exploration and Colonization and the effect it had on the world. In unit 2 you learned how the tyranny and oppressive policies of those European countries caused their colonies and territories to rebel, some successful and some not, in order to gain independence from their ruling government. In unit 2 you studied the beginnings of some of the world's most famous republics in modern history.
Now, in Unit 3 you will learn how the internal politics (domestic) of these republics (aka confederacy) work. As taught in Unit 2, tyranny causes rebellion and revolution, and when revolutions/rebellions are successful it usually results in a representative governments with democratic principles in order to establish consent of the governed. When citizens of a country or state have problems with how their government operates it's called a grievance, or complaint. Revolutions usually start peacefully, with citizens asking governments to make changes (addressing their grievances) through petitions, compromises, and sending delegates to assemblies and conventions to make deals, agreements, and treaties. When states or provinces within a republic disagree with the central (federal) government, another option is nullification, which means to cancel or void laws, which can and has caused conflict throughout the history of republics and confederacies or otherwise representative governments. For example, one prominent use of nullification in both Texas and United States history is the issue of whether or not there should be protective tariffs or a national bank. When peaceful negotiations fail it usually results in conflict, riots, skirmishes, and sometimes in extreme cases, massacres.
The point of constitutions is to mitigate the tension between political parties in order to ensure a functioning government. In order to prevent fracturing and the development of crippling political parties (lol), two groups known as the federalists and antifederalists emerged, the latter of which demanded a compromise to include a Bill of Rights before Ratification.
Unit 3 highlights the different philosophies within a republic. Republics can be federalist (decentralized) or centralist. Democracies and republics, although they limit government, are not immune to tyranny. Republics have complex politics and almost always opposing factions (political parties) competing for support and resources. Depending on the political leanings of republics it affects how independent countries address issues such as imperialism (manifest destiny), annexation and secession, debt, social issues such as education and infrastructure, as well as the allocation of capital (money in the economy). Any and all decisions of governments are subject to criticism from the people, and it's up to the governments as to how those criticism are dealt with, violently or peacefully.