Law usa

The United States Constitution is the the most important law.
Levels of law
1. Federal law originates with the Constitution, which gives Congress the power to enact statutes for certain limited purposes like regulating interstate commerce. Nearly all statutes have been codified in the United States Code.
2. Federal statutory enactment and codification
Main articles: United States Statutes atLarge and United States Code
After the President signs a bill into law (or Congress enacts it over his veto), it is delivered to the Office of the Federal Register (OFR) of the National Archives and Records Administration (NARA) where it is assigned a law number, and prepared for publication as a slip law.
3. Federal regulatory promulgation and codification
Main articles: Federal Register andCode of Federal Regulations
Congress often enacts statutes that grant broad rulemaking authority to federal agencies. Often, Congress is simply too gridlocked to draft detailed statutes that explain how the agency should react to every possible situation, or Congress believes the agency's technical specialists are best equipped to deal with particular fact situations as they arise.
4.Formulation of federal precedent
Unlike the states, there is no plenary reception statute at the federal level that continued the common law and thereby granted federal courts the power to formulate legal precedent like their English predecessors. Federal courts are solely creatures of the federal Constitution and the federal Judiciary Acts.
State law
Main article: State law (United States)
The fiftyAmerican states are separate sovereigns with their own state constitutions, state governments, and state courts (including state supreme courts).They retain plenary power to make laws covering anything not preempted by the federal Constitution, federal statutes, or international treaties ratified by the federal Senate.
Types of law
Procedural law
Traditionally, lawyers distinguish betweenprocedural law (which controls the procedure followed by courts and parties to legal cases) and substantive law (which is what most people think of as law). In turn, procedural law is divided into criminal procedure and civil procedure.
Criminal procedure
The law of criminal procedure in the United States consists of a massive overlay of federal constitutional case law interwoven with the federal andstate statutes that actually provide the foundation for the creation and operation of law enforcement agencies and prison systems as well as the proceedings in criminal trials.
Civil procedure
Main article: Civil procedure in the United States
The law of civil procedure governs process in all judicial proceedings involving lawsuits between private parties. Traditional common law pleading wasreplaced by code pleading in 24 states after New York enacted the Field Code in 1850, and code pleading in turn was subsequently replaced again in most states by modern notice pleading during the 20th century.
Substantive law
Substantive law comprises the actual "substance" of the law; that is, the law that defines legally enforceable rights and duties, and what wrongful acts amount toviolations of those rights and duties.
Criminal law
Main article: Criminal law of the United States
Criminal law involves the prosecution by the state of wrongful acts which are considered to be so serious that they are a breach of the sovereign's peace (and cannot be deterred or remedied by mere lawsuits between private parties). Generally, crimes can result in incarceration, but torts (see below)cannot.
Contract law
The Uniform Commercial Code
Main article: United States contract law
Contract law covers obligations established by agreement (express or implied) between private parties. Generally, contract law in transactions involving the sale of goods has become highly standardized nationwide as a result of the widespread adoption of the Uniform Commercial Code. However, there is...