A growing number of historical scholars in social science and humanities fields are using geographic information systems (GIS) to help investigate spatial questions and map their findings. The nature of historical data and historiographic practices present several challenges in using GIS that have been addressed only partially to date. For example, although events are inherently spatial and a fundamental construct in historical reasoning, there have been few attempts to create comprehensive data models for describing them. Likewise, computational representations of historical processes and narrative remain largely undeveloped. In this research, the emerging genre of digital historical atlas is presented as a broad use case and contextualized. Its representation requirements are detailed in novel conceptual and logical models of relevant geo-historical information constructs, presented as a generalized development framework. An event-centered and information-based spatial history ontology (SHO) was developed by adapting and extending an existing upper ontology (DOLCE). Its implementation in a spatial object-relational database populated with several historical datasets is described. Some important challenges remaining in this large, ultimately collaborative undertaking are discussed.