Continental Can Co. was started in 1904. They made tin cans (mostly steel, with a tin coating to prevent rusting). In 1909, they bought the Standard Tin Plate Co. of Canonsburg (started in 1903) to make sure that the tin can tops were made in steady supply. In 1922, the facility in Canonsburg started making can tops only. In the 1940s, it employed around 425 people. Taken over by Alcoa during WWII.
(On a personal note, my ex-father-in-law worked at Continental Can in Katy, Texas, and he tried to get me to work as an electrician at their factory. It was of no interest to me, but I did get to tour the factory. Even with heavy-duty ear protection, it was still insanely loud in there, with all of those beer cans being formed and routed through the conveyor belts.)