*Association of Religion Data Archives (ARDA)
Interactive site that includes national profiles of religious groups, maps, tables, charts, surveys and reports.
The ARDA allows you to interactively explore the highest quality data on American and international religion using online features for generating national profiles, GIS maps, church membership overviews, denominational heritage trees, tables, charts, and other reports. Over 450 surveys and other data collections are available for online preview and virtually all can be downloaded free of charge.