The first toy robot is believed to be the boxy, yellow, clockwork Robot Lilliput from Japan.. Although many collectors believe this robot to be from the late 1930's, experts are begining to atribute it to the mid 1940's, after the war.
The next Japanese robot to make an appearance, was the late 1940's Atomic Robot Man. This second robot's date of birth is definitely known, since it was given out as a promo item at the New York Sci-fi convention in 1950. The box for Atomic Robot Man showed an ironic scene of the robot marching through a decimated city, complete with an atomic mushroom cloud...
While Japanese toys began to appear in the US shortly after the war, most of the first robots were actually American made. The first to show up in the Sears Christmas Book was Ideal's crank operated Robert the Robot in 1954. Soon came, Marvelous Mike, The Robot Dog, Z-Man, Big Max and Marx Electric robot, all American made. Japan was about to unleash its secret weapon, in 1955 battery operated toys began to arrive from Japan.
Toy Robot History : A brief history of toy robots by Darryl aka The Robotnut http://www.robotnut.com/history/