The U.S. Sentencing Commission was created in 1984 as part of the Sentencing Reform Act provisions that were included in the Comprehensive Crime Control Act of 1984 (28 U.S.C. § 994). The Commission’s principal purpose has been to establish uniform sentencing guidelines and practices for the federal court system. The guidelines provide 43 levels of offense seriousness that take into account not only the seriousness of the crime, but also the offender’s criminal history. They apply to all federal felonies and most serious misdemeanors.

Decisions rendered by the U.S. Supreme Court in 2004 and 2005 altered the use of sentencing guidelines by state and federal courts. First, the Court in Blakely v. Washington (2004) ruled that the sentencing guidelines employed by the state of Washington were unconstitutional. The ruling caused many states to evaluate whether their own sentencing guidelines would survive constitutional muster. Moreover, some lower federal courts ruled that the federal sentencing guidelines were also unconstitutional. The Supreme Court resolved the question about whether mandatory provisions in the federal guidelines violated the Constitution. In two related cases, United States v. Booker and United States v. Fanfan, both decided in 2005, the Court ruled that the federal guidelines were indeed unconstitutional. According to the Court, judges may use their discretion in following the guidelines, but the guidelines may not be mandatory.

Prior to the Blakely decision, many states established their own sentencing commissions. The National Association of Sentencing Commissions (NASC), which includes the federal sector as a member, provides a forum, complete with national conferences, to promote the adoption of uniform or similar presumptive sentencing guidelines among jurisdictions. As of 2005, both the U.S. Sentencing Commission and state governments continued to explore possible means by which federal and state sentencing guidelines could be amended to conform to constitutional requirements.