Advertisement in the Springfield (Mass.) Republican, April 27, 1878, p. 1:
Family Supplies BOCK BEER, BOCK BEER Yuengling & Co's famous Bock Beer has arrived at 190 Main Street. All orders for this celebrated Beer promptly filled, and sent in kegs or bottles to any part of the city or state. M. D. SLEEPER & CO., Springfield, Mass.
Note: In this case, Sleeper served as an agency for Yuengling, and probably bottled the beer using a hand-siphon at its shop in Springfield.