In 1932, carpenter Ole Kirk Christiansen founded his company in Billund, Denmark with the goal of promoting inventive games and creativity in children. He began by producing stepladders. However, the Great Depression forced him into a flexible business model. He turned his attention on the manufacture of toys, and created one of the most loved brands.
Christiansen was a forward-thinking person who was quick to adopt new materials and technologies. In 1947, he became the first company to purchase an injection molding machine made of plastic in the world. This greatly enhanced the possibilities and variety of Lego products. The machine also allowed him to create a prototype that would eventually become an iconic Lego brick. The bricks had pegs on top and hollow bottoms that interlocked with each one another, allowing children to build intricate structures that were far more complex than the possibilities of wooden blocks of the past.
The 1950s were a decade of expansion for the business. Kjeld Kirk Christiansen, Godtfred Kirk Christiansen’s daughter, joined the management team and started modernizing the manufacturing processes of the company. This expansion was accompanied by the launch of a line of dollhouses and furniture for girls, and also the first Minifigures as individual figures. In 1979 the company expanded into space with sets presenting astronaut minifigures, rockets lunar rovers and spaceships and also into the medieval world with a castle theme.
In 1990, the company launched three Model Team sets that were intended for advanced builders. The sets introduced small components like gears, axles, and levers. They also offered the kind of realism and accuracy that was unparalleled in the Lego series at the time.
https://lego-x.com/2020/02/22/a-brief-history-of-the-creation-of-the-lego-constructor