Karel Capek's play "R.U.R." (Rossum's Universal Robots) produced in 1921 (London opening, 1923). - First use of the word 'robot' in English.
Alan Turing proposed the universal Turing machine (1936-37)
Electro, a mechanical man, introduced by Westinghouse Electricat the World's Fair in New York (1939), along with Sparko, a mechanical dog.