The Halsam toy company of Chicago offered the first sets of American Bricks construction sets made of wood in the 1940s. The interlocking stud and socket system that held the bricks together was similar to the blocks in LEGO sets that arrived in the United States in the 1960s. The American Brick pieces were grooved on the outer face to resemble the texture of bricks. These building sets also included windows and doors and special bricks for foundations and lintels. When Halsam changed the wooden bricks to ones made of plastic, it created the Elgo Plastics division to produce the sets, and these were sold in the familiar cylindrical canisters of the 1950s. American Brick sets remained on the toy market into the 1970s, though, by then, the Playskool company had taken over the toy line when it bought out Halsam.