DeCamp became known as a member of the Boston School led by Edmund C. Tarbell and Emil Otto Grundmann, focusing on figure painting, and in the 1890s adopting the style of Tonalism.

A 1904 fire in his Boston studio destroyed several hundred of his early paintings, including nearly all of his landscapes.

He received an honorable mention at the 1900 Exposition Universelle in Paris (for Woman Drying Her Hair).

His exhibit at the 1904 St. Louis World's Fair — Reading – The Sea Wall – Portrait of Arthur P. DeCamp — was awarded a gold medal.

He was awarded the 1909 Clarke Silver Medal by the Corcoran Gallery of Art (for The Guitar Player).