According to policy theorist John W. Kingdon's theory on agenda setting, three streams of problems, politics, and policy alternatives converge to create a window of opportunity that allows an issue to move onto the policy-setting agenda. In 1999 the policy-setting agenda included former President Bill Clinton's class size reduction policy despite many decades of conflict over the policy and inaction at the federal level. It appears that a change in the political stream created a window of opportunity that allowed class size reduction to arrive on the agenda. By examining enrollment data, average class size and teacher-pupil ratio trends, national perceptions, developments in policy approaches, and political factors, this study concludes that class size reduction is an example of Kingdon's theory.