When was the first payphone put on line?

Payphones were preceded by pay stations, manned by telephone company attendants who would collect rapid payment for calls placed. The Connecticut Telephone Co. reportedly had a payphone in their New Haven office beginning June 1, 1880; the fee was handed to an attendant. In 1889, a public telephone with a coin-pay mechanism was installed at the Hartford Bank in Hartford, Connecticut by the Southern New England Telephone Co. It was a "post-pay" machine; coins were inserted at the end of a conversation. The coin mechanism was invented by William Gray; he was issued a series of patents for his devices