Opponents of mass incarceration such as Michelle Alexander have called it the “New Jim Crow,” a social institution aimed at limiting the rights of African Americans. Upon release, felons are legally denied the right to vote, excluded from juries, and placed in a position of subservience. Others suggest that “cultural shifts, political realignments, changes in job prospects for low-skilled men, and, perhaps most importantly, legal changes” have led to the sharp rise and stark disparity in black incarceration rates between the end of the 20th century and the beginning of the 21st century. One thing is certain: mass incarceration would be justifiable if crime decreased, but that's just not the case. Evidence has shown that the benefits of mass incarceration in reducing crime have declined over time, and that incarceration is now a much less effective method of crime control than before the 1990s. Because of the factual evidence of the high rate of racial disparity in prison, mass incarceration can be viewed as a significant generator of social inequality. The history and study of mass incarceration is important because it defines us as a society just as slavery and Jim Crow once did