Born in Weymouth, Massachusetts graves studied both in New England and abroad. He attended the Massachusetts Institute of Technology and continued his studies in Italy and Paris where he roomed with a fellow artist also destined for greatness, Edmond Tarbell.
In 1885 Graves returned to Boston where he became an instructor at the Cowles Art School with another close friend and colleague, the renowned artist Childe Hassam. He returned to Paris in 1887 to study figure painting with Cromen, Laurens and Gervais. Exhibiting widely, Graves became best known for his oils, pastels and watercolors depicting gardens and floral landscapes, but he also painted harbor scenes and very fine figure studies.
Throughout his career, graves continued his travel between New England and Paris. In 1891 he opened his own art school in Boston, moving it at some point to Kennebuncport, Maine where he spent the remainder of his career as an illustrator for Paris magazines and achieving wide acclaim for his garden paintings, which often featured refined figure studies as part of their composition. In 1905 he was honored with a medal at the Paris Expo des Beaux Arts.