About LEGO Universal Building Set Basic Set
LEGO's Universal Building Sets theme was released as early as 1966 but it was not until 1973 that the Basic LEGO sets became known as Universal Building Sets. These sets were produced in two set version numbers, the first was for sets that were sold in the UK, Europe, Canada and Australia. The other version numbers, but for the same exact set with the same box artwork was released in the United States. Most, but not all sets between 1973 and 1981 were sold in both regions.
1966 LEGO Sets
1966 marked yet another important year for LEGO. Not only did the international expansion reach an all-time high with now 42 countries selling LEGO, 1966 was the year LEGO officially released the Train theme. With the advent of the improved 4.5 V electric motor and housing, thanks to the engineering of the LEGO Futura and the process development lab, the introduction of LEGO trains was a natural fit. LEGO developed a number of new elements for the train system, including hook couplers, flanged wheels and, of course, a track system. Several train sets, such as the 113. 114 and 115, were released in 1966 and LEGO began to feature the new system in its catalogs and idea books. The trains, were popular enough, especially in Europe, that LEGO expanded the system with several accessories, most notably an electronic control unit that controlled the motor by a high-pitched whistle.