Spear, who was born in Washington, DC studied at the George Washington University and continued his studies at the Académie Julian in Paris. The artist specialized in genre, fantasy scenes, portraits of nymphs and mermaids as well as more traditional landscape and coastal scenes. He settled in Boston in 1907 and taught at the Fenway School of Illustration.
A 1925 review of his exhibition at Vose Galleries in Boston remarked, “The realm [Spear] chooses to depict is quite his own. No one would dare to essay those particular fancies in which mermaids, lady fauns, nymphs, sprites and other delicious creatures ecstatically swing and sway, or whisk across idyllic scenes.”