Who did James Abbott mcniell whistler paint whistlers mother for?

What we often call "Whistler's Mother" was actually called "Study in Gray and Black." It is only incidentally a portrait of his mother, and was painted for no buyer. He probably painted it as a compositional answer to his fellow artists, who thought he had left the art of painting too far. In other Words, he did it to prove his method was sound, his sensibilities intact. Many artists since have considered it to be one of the very first "abstract paintings."