How does federalism in the United States work? Why are there States within the country? What do they do?
Background on Federalism itself:
Federalism is a method of organizing a country where there are two "levels" of government: the country and its constituent parts. Unlike provinces or departments in a so-called unitary state, these parts have, in theory and practice, significant self-government. They cannot be easily abolished or changed by simple decision of the country's government. In a unitary state this may occur. For example, in New Zealand in 1870 the provinces were completely disbanded by act of the legislature.
Background on federalism in the United States:
In the 1600s and 1700s, England and then Great Britain colonized the eastern coastal part of the north American continent, from what is now Georgia in the south to what is now New Found Land in the north. This was not a unified effort. Each colony was governed separately and had its own charter issued by the monarch of Great Britain at the time of founding. These charters varied, but all had provisions for a elective part of a legislature and a governor from either the monarch (such as in Massachusetts) or the company that owned the colony (such as Pennsylvania). These latter were termed "proprietary" colonies, governors, etc.
At the time of the Revolutionary War, thirteen of the colonies declared themselves independent of their colonial mother country (Great Britain). This was done via extra-legal means: the royally appointed governors refused to countenance the elected assemblies treasonous (to them) declarations, so the assemblies met as "provincial" congresses and declared themselves the lawful assemblies and independent States.
Critically, although the thirteen colonies banded together immediately under the first constitutional document of the United States, the Articles of Confederation, they did this of their (provincial congress's) free will. After the war and some trouble with the existing confederal* government, they, again individually, agreed to replace the Articles of Confederation with the new, current, Constitution.
- Do not confuse the confederal union here with the much later Confederate States that fought and were defeated in the Civil War.
Because of this history, the States of the Union are the originators of the powers of government in the United States. When they ratified the Constitution, they agreed to mutually cede equal amounts of power to the new Federal government. These powers are listed in article 1, section 8 of the Constitution and are termed the "enumerated powers".
Although written in quaint terms, they essentially comprise what the authors of the Constitution (termed "framers") thought a country on the international and internal stage needed to be able to do. Similarly, they listed a few things that the States could NOT do, like have foreign relations. These were to be the domain of the Federal government alone.
Various amendments were added to the Constitution soon afterwards in order to protect the people from the Federal government. Ten of these twelve were ratified and made a part of the Constitution to be termed the "Bill of Rights". The last one was ratified approximately 200 years later.
Although not given the power to do so explicitly, the Supreme Court of the United States is by all agreed to have the power to determine "what the law is". Persons regularly think that laws the Federal or State governments have passed are against the Constitution. They bring law suits against the persons who are, by law, required to enforce them, and seek to have the Federal court system, possibly the Supreme Court, declare them "unconstitutional". When the court does so, it declares the law in question to be unenforceable and void. The only ways to change this are via a change to the law, so it is constitutional now, a change to the Constitution or a later decision of the court.