William Gray invented the pay phone (coin-operated call box to you Brits) by 1889. It was first installed in the Hartford Bank, Hartford, Connecticut, by the Southern New England Telephone Company in 1889. In 1891, William Gray formed the Gray Telephone Pay Station to rent out coin-operated telephones to store owners.
Making a secure and reliable pay phone turned out to be tough to do, and in 1889 William Gray got a patent for an innovative coin payment mechanism he was able to defend for decades. Gray distributed its pay stations through other companies including Western Electric, ultimately selling out to Automatic Electric.