Emory University Library has a rich collection of missionary-related primary source materials.
Click here for an overview of their Mission Collections on microfilm.
Emory's Manuscripts, Archives, and Rare Books Library (MARBL) also has materials relating specifically to Methodist history, including missionary materials. Click here to see their Methodist History research guide.
The Yale University Divinity School Library has a comprehensive research guide on Missions and World Christianity, including information on digital libraries relating to missionaries and mission work.
Call numbers are specific to Yale. You can look up these resources in GIL or GIL-Find.
To find primary (and also secondary) sources in GIL or GIL-Find on missionaries, try subject searches using these terms: