In 1941, he established his architectural practice in Wilkes–Barre. In 1943, Atherton expanded his solo practice into the partnership of Lacy & Atherton with James O. Lacy. In 1945, John W. Davis joined them, becoming Lacy, Atherton & Davis. Their offices were located in the Hotel Sterling Building in Wilkes–Barre. They were registered to practice in New York, North Carolina, Ohio, and Pennsylvania. He retired from the firm in 1970.
