In 1969 LEGO released the 12 volt train sets as part of the Blue Era which was named because of the rail color. These 12V train sets used additional conductor rails mounted between the standard 4.5V rails and 12V motors contained in the same housings as the 4.5V motors, but with additional metal contacts attached to the bottom of the housings.
1970 LEGO Sets
By 1970, LEGO’s workforce had grown to over 1,000 employees, reflecting its continued expansion. This year also marked the beginning of LEGO’s efforts to regain control of the U.S. market from Samsonite. Following the death of Samsonite’s founder, Jesse Shwayder, LEGO started the process of reclaiming the LEGO license in the United States. By 1973, LEGO would take full control of its U.S. sales and operations.