As the story goes, Alfred C. Gilbert invented the Erector set by observing the steel work along the New York, New Haven Railroad, in 1913. Although there were other metal construction toys available, the most prominent of which was Meccano made by Hornby in England. Gilbert along with John Petrie had started the Mysto Magic Co. in 1909. Gilbert, a graduate of Yale Medical School, had won a gold medal for pole vaulting in the 1908 Olympics in England.

Most of the available metal construction sets were simply pulleys, gears, and varying lengths of metal strips with holes evenly spaced on them. Metal construction sets were very popular, especially with boys. Gilbert had what he saw as a better idea. He wanted something more sturdy, and what he came up with was a way of making a ridged square girder. And so the Erector set was born. Gilbert's Erector sets also included the pulleys, gears and wheels,but it also had wider strips, triangles and other shapes. The main girder was formed by 4 strips held together by only 2 screws to form a very sturdy square girder. The first sets were numbered 1 to 8, the higher the number, the more parts to make more things. The smaller less expensive sets came in cardboard boxes, more expensive sets were in study wooden boxes. Also included in the large sets was an electric motor.

As time went on the original Erector set went through many changes. In 1924 the main girders were changed from the original 1" wide to 1/2" wide. This was evidently done so smaller curved girders could be added. With this smaller curve, a wider variety of models could be built. This include a ferris wheel and zeppelin. Also included in other sets were parts to build a truck.

One of the most impressive change came in 1931, with the Erector Hudson Locomotive and Tender. You could build an entire large working train locomotive. While some sets were always offered in some kind of cardboard box or tube, the wooden box was replaced by metal boxes. But if the ferris wheel, zeppelin and Hudson weren't impressive enough, then the 1940 Parachute Jump, one of the largest and most detailed models, to that time, had to be an eye grabber. Gilbert also added many accessory items for Erector, such as lighting kits and smoke units.

And changes and new sets kept coming through the 1950's. There were the theme sets, like the Amusement Park set, the Cap Canavril set and many more. The largest set ever offered was the 12 1/2, with this set you could build one of the most popular things of the day, a robot.

In the 1960's the Gilbert Company fell on hard times. Sales of it's two biggest selling toy lines, Erector and American Flyer Trains fell off. After the death of A.C. Gilbert Sr., his son took over for a short time. The company was eventually acquired by the Wrather Corporation, which drove it into ruin. In 1966 the Company was liquidated, Erector was purchased by Gabriel Toys, and later by CBS, and is now owned by Meccano.