Cornelia Cunningham was born in Savannah, Georgia, December 2, 1903 to Malcolm Cunningham (1860-1933) and Frances Adaline Jones Cunningham (1872-1944). Cornelia graduated from Savannah High School in Savannah, Georgia, and Women's Art School in Cooper Union, New York. She attended Grand Central Art School in New York, New York, the National Academy in New York, New York, and Berkshire Summer School of Art in Monterey, Massachusetts. She moved to Atlanta to live with her aunt and uncle and opened an artist studio in 1926. She belonged to several clubs including the Studio Club of Atlanta, the Atlanta Art Association, Atlanta Woman's Club, Telfair Art Academy, and the Savannah Association of Georgia Artists.

Cornelia Cunningham married James Teller Schoolcraft, Jr. (b. 1900) on April 30, 1935 in Atlanta, Georgia. They were divorced by 1941. Cornelia married Reverend Ralph Singleton Huffer in Basingstoke, Hampshire, England, in September 1951. Cornelia died in March 1974 in New Hampshire.

Cornelia contributed her artistry to several published works. In 1932, she drew a historical map of Georgia for the state bi-centennial. She illustrated a children's book in 1933 titled Spaniard's Mark, by Allan Dwight. In 1933, Cornelia published her own book of drawings, Atlanta: City of To-Day, which showcased twenty-four of her original sketches of historic sites and street scenes around the city. In 1937, Cornelia supplied the cover art for a booklet on the Wormsloe Plantation in Chatham County, near Savannah. She also illustrated the cover for Thirteen Sonnets of Georgia, by Daniel Hickey in 1941.