At the end of each legislative session the slip laws are compiled and published as Statutes At Large. Once published, slip laws become Session laws. Statutes at Large are the official source for the laws and concurrent resolutions passed by Congress.
In 1845 Congress passed a resolution that granted publication authority of Statutes at Large to the publication company of Little, Brown & Company. In 1947, publication authority was granted to the Governmental Printing Office. Over the next few decades the responsibility floated from one government office to another until 1985, when the Office of Law Revision Counsel took over.
After printing the session laws, the Office of Law Revision Counsel placed them into the United States Code.
In the Statutory citation, the first number is the volume number of the edition of Statutes at Large, and the second number is the page number upon which the Statute is found.