Construction set:American Plastic Bricks Set No. 725

The Elgo division of the Halsam toy company of Chicago began making plastic American Bricks construction sets in the 1940s. The interlocking socket system that held the bricks together was similar to the blocks in LEGO sets that arrived in the United States in the 1960s, but the Elgo blocks were grooved on the outer face to resemble the texture of bricks. American Bricks also included windows and doors and special bricks for foundations and lintels. The American Brick sets continued on the toy market into the 1970s, though, by then, the Playskool company has taken over the toy line.