The Federal Rules of Evidence govern the admission or exclusion of evidence in most proceedings in the United States courts. The Supreme Court submitted proposed Federal Rules of Evidence to Congress on February 5, 1973, but Congress exercised its power under the Rules Enabling Act to suspend their implementation. The Federal Rules of Evidence became federal law on January 2, 1975, when President Ford signed the Act to Establish Rules of Evidence for Certain Courts and Proceedings, Pub. L. No. 93-595. As enacted, the Evidence Rules included amendments by Congress to the rules originally proposed by the Supreme Court. The most recent amendments to the Federal Rules of Evidence were adopted in 2014.

http://www.uscourts.gov/file/rules-evidence