American Chess Company was offering chess clocks, which were based on the Waterbury movements, already since 1904 (famous Cambridge Spring clock), initially following the conventional ‘buttons’ design. First evidence of the Waterbury ‘pushbar’ clock appears as an Ad in the American Chess Bulletin only in 1917. Basis for this model was a Clock ‘Transit’, known from Waterbury Catalogues since 1914-1915. Solid dimensions, absence of flags and a revolutionary, at least for the US market, pushbar mechanism (eventually inspired by Dutch 'San Sebastian' model). Photo: 9 years old Samuel Reshevsky playing with Edward Lasker in Julius Rosenwald home (who is also sitting at the table), 1921. There is also another perspective on that game, where Edward is clearly presses a pushbar.

Another model of the Waterbury chess clock, offered by American Chess Company in the early 1920th. It was firstly advertised in 1917 in the American Chess Bulletin: despite not having an exact photo, a key feature of the new model has been clearly described: (...the dials are enclosed in cases covered with dark green leatherette, preventing the access of dust). This clock was preferred by the chess members of the famous Mechanics Institute, evidenced in a game between Samuel Rzeszewski vs. Edward Lasker (1922) and used in the 9th US Chess Congress (1923).