The LEGO Group calls a product line a “theme,” but for the sake of clarity I will be calling them product lines. Until 1978, most LEGO® products reflected Danish society becoming increasingly urbanized (as was the case throughout the Western world).
According to The LEGO Group, “The economic growth of the 1950s means that many Danes can afford to own a car. With an increasing number of cars in the streets, there is a growing focus on teaching children how to behave in traffic. With this in mind, the LEGO Group launches the Town Plan in 1955 as a supplement to the LEGO System in Play products (LEGO® bricks). The Town Plan is a thin piece of plastic cloth (followed later by a cardboard version) showing a stylized network of streets on which children can arrange their LEGO buildings and cars to create an urban setting. The town plan is created in collaboration with the 1950s equivalent of today’s´ Danish Council for Road Safety and can be supplemented with LEGO street signs, small plastic cars and lorries and miniature police officers to direct the traffic.”
In the 1960s, basic LEGO® sets were called Universal Building sets. These were large sets of LEGO® bricks of various sizes. A child’s parents, grandparents, uncles and aunts, etc. could expand his or her collection with supplementary sets.
The LEGOLAND® product range lasted as such from 1969 to 1975. Initially, the name LEGOLAND® did not appear on boxes, only in catalogues and price lists.
In 1970, the name LEGOLAND® began to appear on boxes. As one might guess, the name of this product range was inspired by the company’s original theme park in Billund, Denmark, now called LEGOLAND® Billund, which opened in 1968.
It included houses and vehicles. In the first year of the product range’s existence, these were considered supplementary sets.
In 1970, the sets with houses and small vehicles began to have LEGOLAND® on the packages. The large vehicles were still considered supplementary sets.
The next year, The LEGO Group divided the product range in two: LEGOLAND® houses and LEGOLAND® cars. In 1974, the company introduced LEGOLAND® ships.
Two years later, The LEGO Group dropped the LEGOLAND® name from packages. The sets started to be marketed as Model sets.
In 1978, founder Ole Kirk Christian’s grandson and Godtfred Kirk Christiansen’s son, Kjeld Kirk Kristiansen (who spells the surname differently), introduced a new business model called the System within the System with LEGOLAND® Town, LEGOLAND® Castle, and LEGOLAND® Space. LEGOLAND® Town was rooted in the 1955 LEGO System of Play’s Town Plan.
New base plates have roads printed on their surfaces for LEGO® cars. They plates also had studs so a child could snap building bricks onto them.
In 1991, The LEGO Group changed the name from LEGOLAND® Town to LEGO® Town. Eight years later, in 1999, The LEGO Group changed the name again to LEGO® City.
During a two year period, 2003-2004, the name changed again to LEGO® World City, before it reverted to LEGO® City. Over time, The LEGO Group has introduced what it calls sub-themes, including Airport, Arctic, Coast Guard, Harbor (spelt Harbour in the U.K.), and Mining.