The Fair Sentencing Act of 2010 was signed into (federal) law in August of 2003 and eliminated the difference in mandatory prison time for crack cocaine versus powder cocaine. Previously, the Ant-Drug Abuse Act of 1986 had created strict mandatory minimum sentences for crack cocaine. At the time, crack was a new drug epidemic that was associated with high levels of violence.
Under the 1986 law, federal penalties for possession of crack cocaine were 100 times the penalties for powder cocaine. A person convicted for possession of 5 grams of crack cocaine faced a five year mandatory minimum sentence. For powder cocaine five year mandatory minimum sentences were only required when there was 500 grams of cocaine. For 10 grams of crack cocaine or 1 kilogram of powder cocaine, there was a 10 year mandatory minimum sentence required.
Disparity in sentencing between ponder and crack cocaine has never been supported by fact. Proponents of the harsh penalties argued that crack cocaine was more addictive, but this was proven to be untrue in a 1997 study. The 100:1 penalties for crack cocaine were experienced by African-American males more than any other group. Over the years violence that was once associated with crack distribution declined so that it is not a major concern for law enforcement and is not on the radar of popular opinion.
On June 30, 2011 the U.S. Sentencing Commission announced that it had approved retroactive application of the Fair Sentencing Act (PDF). The Commission estimates that 12,000 prisoners would be eligible for sentence reduction, and that the average reduction in sentence would be 37 months. Every prisoner who requests reduction of their sentence under this provision will appear before a federal sentencing judge to determine his sentence.
http://en.wikipedia.org/wiki/Fair_Sentencing_Act
http://www.washingtonpost.com/wp-dyn/content/article/2010/08/02/AR2010080204360.html