In 2005, the United States Supreme Court ruled in two cases (United States vs. Booker and United States vs. Fanfan) that the Federal Sentencing Commission would assume an advisory role as opposed to a presumptive one in Federal sentencing decisions. One of the chief concerns following these decisions was that they would result in unwarranted racial and ethnic disparity in sentencing. A report by the United States Sentencing Commission (USSC) in March 2010 found that racial disparities in sentencing increased after the two decisions. This study repeated the USSC study to determine if the findings were correct. This current study found that while racial disparity increased after the decisions by the U.S. Supreme Court, the factors causing the increase were not strictly related to the changes in the Federal sentencing guidelines. For Black males, increases in sentence-length disparity were the result of imprisonment decisions, not sentence-lengths. The study also found that criminal histories of defendants had an effect on sentences independent of the guidelines presumptive sentences, and that these criminal histories mediated a notable portion of the racial disparity attributed to just being a Black male. Study limitations are discussed. Figures, tables, and references