The process of recreating a past version of the law involves examining the statutory history at the end of relevant code sections currently in force or examining earlier editions of codes. Annotated codes often provide helpful information in notes discussing legislative history. Non-New England state codes are shelved in the state primary room on the second floor of the older part of the building. New England state codes are shelved in the New England Room on the second floor of the addition. There are several copies of the M.R.S.A. in the Reading Room on the third floor.
Many codes are available through the Internet.
Both the slip law and bound versions give public law and U.S. Code designations. A commercial version of the U.S. Statutes at Large is published by West. This set is especially useful in compiling federal legislative histories as it provides citations to bill numbers, committee reports, references to dates of consideration and passage of bills, and reprints of selected committee reports. The official U.S.C. is published in full every six years with annual supplements issued in the interim. It does not have annotations and is usually two to three years out of date.