The present invention embodiments include a geographic overlay system including an information system, a mapping system interface to communicate with a mapping system and a database system including National Census geographic boundaries and data files. The geographic overlay system utilizes a client/server model that streams geographic data from a server system to dynamically render vector-based map layers inside a client browser. The geographic overlay system employs a Nationwide database of Census geographies that may be rendered as interactive point, line or polygon objects over a National base map provided by the mapping system. A database builder interface enables users to build the database and server pages. The present invention embodiments overlay translucent, interactive dynamically generated vector-based polygonal Census boundary map layers over geographical maps from the mapping system. The overlaying vector map layers perform thematic analysis, enable information retrieval, display mouse-over tool-tips and query a dynamic block-level National spatial-relational database.