This is a resource for the Archives of the Billy Graham Center. This archive is different in that it is not an archive of a particular denomination but instead is an archive of an activity-that of evangelism. The Archive includes oral histories, papers of individuals and records of organizations.
This is an interesting eclectic collection of items, numbering 500 collections, that may be of interest to those whose ancestors were missionaries or were involved in some sort of evangelical endeavor for a Christian church.
For more information about the Archives check out, http://www.wheaton.edu/bgc/archives/genealogy/genelecture.htm