He was delivered by his maternal grandmother, Dr. Martha Ann Canfield, who was among the earliest women to practice medicine in Northern Ohio.

There, he studied the art and culture of the American Plains Indians under Clark Wissler; he received his master's degree with Honors in 1934.

[5] In 1946, after two years of service with the US Navy in the Pacific during World War II, Ewers joined the Smithsonian Institution as Associate Curator of Ethnology.

[9] A memorial service was held for him on June 17, 1997, at the Carmichael Auditorium in the National Museum of American History.

[10] After his death, the Western History Association established the John C. Ewers Prize, awarded biennially for the best book on the North American Indian ethnohistory.

In 2011, The University of Oklahoma Press published Plains Indian Art: The Pioneering Work of John C. Ewers.

The latter book, edited by his daughter Jane Ewers Robinson, is a collection of her father's writings that were originally published in American Indian Art Magazine and other periodicals between 1968 and 1992.

He also edited and wrote the introductions to 19th-century accounts of American Indian culture by Zenas Leonard, Edwin Thompson Denig, George Catlin, and Jean-Louis Berlandier.