Public Laws vs. Private Laws: Public laws are laws intended for general application, such as those that apply to the nation as a whole or a class of individuals. Private laws are enacted for the benefit of a particular individual or small group, such as claims against the government or individual immigration or naturalization matters.
United States Statutes at Large: Abreviated in citations as 'stat.", the U.S. Statutes at Large is the official publication of all public and private laws and resolutions from 1789 to present. Until 1948 all treaties (including treaties with Native Americans) and international agreements were also published in U.S. Statutes at Large. The Declaration of Independence, Articles of Confederation, U.S. Constitution and its amendments are also published in U.S. Statutes at Large.
Slip laws: Before laws are published in the United States Statutes at Large, they are first available as slip laws. A slip law is just an individual law, published on its own in a small pamphlet. Slip laws are widely available on the internet, especially with regard to legislation passed during the last few decades.