Scope and Contents: These papers primarily consist of Greenwalt's letters to his parents while he volunteered for the Civilian Public Service (CPS) during World War II. Greenwalt, a conscientious objector and member of the Mennonite Church, describes in his letters his work in fish and wildlife preservation. These letters provide insight into World War II conservation practices. Other materials in these papers include his application for conscientious objector status, newsletters and ephemera he collected while serving, and miscellaneous correspondence.