First adopted in 1975, the Federal Rules of Evidence codify the evidence law that applies in United States federal courts. In addition, many states in the United States have either adopted the Federal Rules of Evidence, with or without local variations, or have revised their own evidence rules or codes to at least partially follow the federal rules. History The law of evidence governs the proof of facts and the inferences flowing from such facts during the trial of civil and criminal lawsuits. Before the twentieth century, evidence law was largely the product of decisional law. During the twentieth century, projects such as the California Evidence Code and the Uniform Rules of Evidence encouraged the codification of those common law evidence rules. In 1965, Chief Justice Earl Warren appointed an advisory committee of fifteen to draft the new rules. The committee was composed of U.S. lawyers and U.S. legal scholars. The Federal Rules of Evidence began as rules proposed pursuant to a statutory grant of authority, the Rules Enabling Act, but were eventually enacted as statutory law. The United States Supreme Court circulated drafts of the FRE in 1969, 1971 and 1972, but Congress then exercised its power under the Rules Enabling Act to suspend implementation of the FRE until it could study them further. After a long delay blamed on the Watergate scandal, the FRE became federal law on January 2, 1975, when President Ford signed An Act to Establish Rules of Evidence for Certain Courts and Proceedings, , . The law was enacted only after Congress made a series of modifications to the proposed rules. Much of the debate on the Rules stemmed from concerns that came to lawmakers' attention due to the Watergate scandal, particularly questions of privilege. Some of the most prominent congressional amendments when Congress adopted the rules included: Prior Inconsistent Statement – Rule 801(d)(1)(A): Congress amended the proposed rule so that the "rule now requires that the prior inconsistent statement be given under oath subject to the penalty of perjury at a trial, hearing, or other proceeding, or in a deposition. The rule as adopted covers statements before a grand jury." Privileges – Rule 501: Although the original proposal included thirteen rules providing for various privileges, Congress struck all of them. To guide privileges in the federal courts, Congress adopted Rule 501. The rule specified that except as otherwise provided by Act of Congress