When did pushmatic breakers come out?

Pushmatic breakers first came out in the early 1950s, introduced by Bulldog Electric Products Company as an innovative push-button circuit breaker design. Bulldog Electric, founded in Detroit, Michigan, pioneered the Pushmatic system where breakers are activated by pushing a button rather than flipping a switch, which was considered a novel and compact design at the time. Pushmatic panels and breakers were widely installed in residential homes from the 1950s through the 1970s, particularly during the post-World War II housing boom when demand for affordable electrical panels was high. In the 1960s, Bulldog Electric was acquired by ITE Imperial, and Pushmatic breakers continued to be sold under the ITE Pushmatic brand, and later ITE was acquired by Siemens, which continued to support Pushmatic for a time. Production of Pushmatic breakers continued through the 1980s, after which they were discontinued as more modern thermal magnetic breaker designs from Square D QO, Cutler-Hammer now Eaton, and Siemens became standard. So Pushmatic breakers were introduced around 1950 to 1952 and were used for about 30 years until the early 1980s, making any existing Pushmatic panel today at least 40 years old and considered outdated by modern electrical standards.