By Art VI, clause 2, of the United States Constitution, our nation has at least three types of Supreme Law which will prevail over contrary state law. The U.S. Constitution is supreme over all other forms of law in this country. The "laws of the United States" (statutes enacted by Congress) and "treaties...made under the authority of the U.S." must yield to the commands and prohibitions of the Constitution. Beyond that, federal statutes and U.S. treaties are considered equal in authority and will prevail over contrary law enacted by any one of the fifty states. In cases of conflict between federal statute and U.S. treaty, that which is later in time will normally prevail.
In essence, treaties are contracts between the United States and foreign nations. Because there are thousands of topics that may be of concern in our relations with foreign states, treaty provisions (that is, treaty law) may frequently cover areas of internal or "domestic" U.S. concern. It is normal to think of law as constitutions, statutes, regulations, and cases; as a result, legal researchers often forget or may be unaware that treaties can also play a crucial role in United States domestic law.
U.S. treaties are first published as separate pamphlets (called "slip treaties") in a series called the Treaties and Other International Acts Series (T.I.A.S.). Each treaty is numbered consecutively; example: T.I.A.S. 2301, T.I.A.S. 2302, etc. These slip treaties are found in: US GOVT DOCS: S 9.10.
U.S. treaties published prior to 1950 can be found in the bound volumes of the U.S. Statutes- at-Large. They can also be found in Bevans, C.E., Treaties and Other International Agreements of the United States, 1776-1949. (U.S. GOVT DOCS: S 9.12/2)
Since 1950, treaties are published in bound volumes of U.S. Treaties and Other International Agreements (U.S.T.). Example: Maritime Boundaries Treaty, U.S. and Mexico, 29 U.S.T. 196 (1976).
Located in: U.S. GOVT DOCS: S 9.12.
Both TIAS and UST are about eight (!!!) years behind. Recent treaties are published commercially in Hein's U.S. Treaties and Other International Agreements - Current Microfiche Service. Look in Microform Cabinet A13. The printed index-binder for the microfiche is on top of cabinets.
In addition, Dispatch is a bi-weekly publication of the U.S. Dept. of State. Many issues carry a section entitled "Treaty Actions" where one can find the very latest developments in U.S. treaty law.
Contrary to popular use of language, the President (not the Senate) ratifies, treaties. Prior to ratification, the President submits a relatively small number of treaties to the Senate with a request for the constitutionally mandated two-thirds affirmative vote of advice and consent. Information on treaties pending before the Senate can be found in Senate Executive Documents, Senate Treaty Documents, and Senate Executive Reports. The library has complete collections of these materials, mostly in microform. Locate what you need with the Index to Senate Executive Documents and Reports, the CIS Index, or the Monthly Catalog of U.S. Government Publications. The CCH Congressional Index (Senate volume) provides status tables for treaties awaiting Senate action.
Sometimes, the U.S. has signed a treaty, but for some reason (e.g., lack of Senate advice and consent, treaty requirement of minimum number of parties not satisfied), the treaty never went into force for the U.S. For such treaties, see: Wiktor, C. Unperfected Treaties of the United States, 1776-1976.
