DeCamp received his early training in the Cincinnati School of Design, under Frank Duveneck, and continued his studies later in the Royal Academy at Munich. He was a member of the group of art students who accompanied Duveneck to Munich, Florence, and Venice, in 1878. In the company were Alexander, Twachtman, Chase, Vinton, MacEwen, Rolshoven, Currier, Grover, Bachcr, and others. This band of students attained a certain celebrity; they figured in fiction as “the Inglehart boys” in William Dean Howells’s Indian Summer (1885). There can be no doubt as to the marked influence of Duveneck’s personality and principles on all the young men. Though few of them remained as consistent adherents "of the Munich methods as their leader, none of them failed to make his mark in his own way.
De Camp returned to America in 1880 and settled in Boston, where he was soon recognized as a sound and capable portrait-painter and an efficient teacher.
He was for many years instructor in the Massachusetts Normal Art School. He held to the fundamental essentials of his art, especially good drawing and firm construction. De Camp’s home was in Medford, and his studio was in Boston.
His death occurred at Bocagrande, Florida.
In 1911 he exhibited seventeen pictures there, including his full-length portrait of Theodore Roosevelt, presented by his classmates to the Harvard Union; a portrait of Frank Duveneck; a self-portrait; and likenesses of Sally and Polly, the artist’s daughters.
He was also a regular exhibitor at the Guild of Boston Artists, the annual exhibitions of the Ten Americans, and the Pennsylvania Academy.
His best- known figure pieces are: “The Pink heather, “The Guitar Player, ” “The Fur Jacket, ” “The New Gown, ” “The Blue Cup, ” “The Window, ” “La Penserosa. ” Ten of his works were in the retrospective exhibition of the Ten Americans, 1908.
His works may be seen in the permanent collections of the Cincinnati Museum, the Boston Art Museum, the Worcester Art Museum, the Pennsylvania Academy of the Fine Arts, the Wilstach collection, Memorial Hall, Philadelphia, and the Boston Art Club. Among his last works were his portraits of Prime Minister Borden of Canada and Gen. Currie, commander of the Canadian forces in France (1919); also a noteworthy picture of the elderly negro chef of the Porcellian Club, Harvard University, in the act of bringing to the table a roast suckling pig.
Many of De Camp’s best paintings were first shown at the St. Botolph Club, of which he was a member. De Camp was a member of the National Institute of Arts and Letters, the Portrait Painters, the Ten Americans, associate member of the National Academy of Design, member of the Philadelphia Art Club, the St. Botolph Club, and the Guild of Boston Artists.
DeCamp's friend George R. Agassiz spoke of his courage, honesty, and humanity; “under a somewhat rugged exterior lay the simplicity and tender-heartedness of a child. "
In September 1891 DeCamp married Edith F. Baker, daughter of Joseph E. Baker, lithographer, a colleague of Winslow Homer in Bufford’s shop, Boston, 1855-57.