In prior research and development (in part supported by a 2014 ED/IES SBIR award), the project team developed Mission U.S., a series of web- and app-based games for topics in U.S. history. With this Phase I funding, the team will extend Mission U.S. by developing and testing a prototype of a virtual reality (VR) platform to immerse students in transformational moments in U.S history and to guide document-based investigations. The prototype of Mission U.S.: Time Snap will consist of VR goggles that present history content, and a website to host mission briefs to prepare student inquiry, worksheets to facilitate reflection, and an embedded assessment. At the end of Phase I in a pilot study with 30 students in one classroom, the researchers will examine whether the VR platform and the website function as planned, if students are engaged with the system, and whether student content knowledge of a historical event improves from pre- to post-test.