Mainly James Constantine Pilling’s incoming correspondence, 1881-1894, with U.S. and Canadian missionaries, church officials, ethnologists, historians, and others regarding Indian languages, publications in Indian languages, and missionaries to the Indians.

Correspondents include John Campbell, Joseph Mary Cataldo, Charles Ami Cutter, James Owen Dorsey, Paul Durieu, Matilda Ridout Edgar, William Davis Ely, Andre´ Marie Garin, Alfred Campbell Garrioch, Emile Grouard, Charles Harrison, John Horden, Samuel Pearce Merrill, Anthony Morvillo, Alfred Longley Riggs, Ann Eliza Worcester Robertson, John Wentworth Sanborn, Samuel Miller Sener, John Dawson Gilmary Shea, James Gilchrist Swan, Alexandre Antonin Taché, and Eugene Vetromile.