Theresa Wilcox Powers was the daughter of Frank P. Wilcox, originally of Springfield, Massachusetts. She inherited through him a portrait of Mary and Francis Edward Wilcox, commissioned by their parents in 1845 of the American "naive" artist Joseph Whiting Stock [1815-1855]. Both small children were in fact deceased before the work was executed. Theresa passed the portrait (now in the NGA), probably by inheritance at her death, to her niece, Josephine Powers Clapp (Mrs. R. Duncan Clapp)of Sarasota, Florida, in 1949.