He and John William Kitson joined forces in 1874 before the 1876 Bi-Centennial as Robert Ellin and Company.
In 1872 Robert Ellin was elected a director of the Bay of Fundy Red Granite Company located in St. George, New Brunswick, Canada; Perth Amboy Terra Cotta Works; 1893 The Goodsell Marble Company Newark NJ.
He was active in establishing the Metropolitan Museum of Art and was an officer of the Sculpture Society covering stone.
Much of the finest work done by Ellin & Kitson has been in the magnificent group of private residences which have been the nucleus of our American art life ...sculpturing formalizing their partnership with emphasis in churches.
At the time of his death, Ellin, Kitson & Co were working on Senator Clark of Montana's NYC home.