The Institute of Education Sciences (IES), an independent, non-partisan statistics, research, and evaluation arm of the U.S. Department of Education has funded a three-year study led by the Educational Development Center in collaboration with ASHP/CML, WNET, and Electric Funstuff. The Mission US series is one of the most widely used supplemental history interventions in the country with over 100,000 registered teachers and more than three million student users. Over the past decade, small scale studies of the games provided evidence for positive effects on students' understanding of historical content and thinking skills, but the efficacy of Mission US series has not yet been examined with larger scale and rigorous methodology. This new grant will address that gap and we look forward to sharing the results.