James Constantine Pilling was born on November 16, 1846, in Washington, D.C.

He was a Congressional stenographer-transcriptionist and a pioneering ethnologist. He was educated at Gonzaga College. He taught himself Pitman shorthand while still in grade school, becoming a highly proficient stenographer. In 1875, he was hired to help administer the U.S. Geological Survey of the Rocky Mountain regions. In 1879, Pilling became the chief clerk of the U.S. Geological Survey and the U.S. Bureau of Ethnology. He was also responsible for the development of the Bureau’s library and for maintaining its archives system. In his free time, he compiled a series of extensive bibliographies of the cultures, mythologies, and languages of the North and Central American aboriginal peoples. In 1885, he published his 1,200-page "Proof-sheets of a Bibliography of North American Indian Languages".

In 1873, he married Emma Theresa Young (1847–1877), and in 1888, he remarried Marry “Minnie” Lois Harper (1860-1940). He died on July 26, 1895, in Olney, Montgomery County, Maryland