De Camp was a pupil of Frank Duveneck and of the Royal Academy of Munich.
After studies Joseph spent time in Florence, Italy, returning to Boston in 1883.
He became a member of the society of Ten American Painters, and a teacher in the schools of the Pennsylvania Academy of Fine Arts, Philadelphia, and the Boston Museum of Fine Arts.
He painted important mural decorations in the Philadelphia city hall.
He was a member of the society of Ten American Painters.
In 1891, De Camp married Edith Franklin Baker. They had four children. Family members served as models for a number of his paintings.