Google Maps API (Application Programming Interface), released in late June 2005 by Google, is an amazing technology that allows users to embed Google Maps in their own Web pages with JavaScript. Google Maps API has accelerated the development of new Google Maps based applications. This article reports a Web-based interactive mapping system building with Google Maps API, to map all Arkansas public schools and linking the school on the Google map with its longitudinal educational achievement database. The goal of this system is to disseminate the longitudinal statistical summaries of school performance produced by experts with the school geographical information to public users. Educators can use this interactive mapping system for local educational research, and for analyses of school improvement through accessing the longitudinal educational achievement data. Parents can use this system to get information for deciding which school would provide the best educational environment, so that they can choose the best and nearest school for their children.