Many of the greatest human innovations in our life were invented by accident. Penicillin, smoke detectors, super glue, chocolate chip cookies, and even toys like Silly Putty and the Super Soaker (of Nerf fame). But I think the Slinky was one of the most innovative of them all. Silicone balls and squirt guns are one thing, but this thing, as simple as it looked, was unlike any other toy on the market. The reason why it became such a huge phenomenon was partly because it practically advertised itself. All a kid had to do was see another kid play with it once, and that was enough for them to want one of their own. It made its toy store debut in the 1940s, but to this day it’s one of the most addictive toys out there simply because there’s nothing else in the world that looks, feels or moves anything like it.

The father playing with his son in the image above is a man named Richard T. James, an American naval engineer from Philadelphia who was trying to come up with a way to keep sensitive ship cargo like gunpowder safely suspended during rough sea travel, with his idea being to create a spring-like safety mechanic. But after accidentally dropping the spring and witnessing its walk-like movement, his inner child woke up and it hit him that he might have an idea for a new toy on his hands.

He sold his wife Betty James on the idea and the two of them teamed up to found the James Spring & Wire Company (later known as James Industries) in order to mass-produce the invention. When Betty James was flipping through the dictionary trying to figure out what to call it, she came upon the word “Slinky,” which means “graceful and sinuous in movement, line, or figure.” After that obvious BINGO of a name, Richard and Betty made 400 copies of 80-foot twisted metal coils, although the journey to find a toy store willing to sell them was a hard one, until they reached out to a department store called Gimbels, which decided to carry the toy during the 1945 Christmas season and cheaply sell them for a dollar each. As it was not the flashiest toy in the store in terms of its aesthetic, Richard T. James quickly realized the best way to sell it was to show a demonstration to the public. The result? It sold out in one day.

The Slinky remained popular until the 1950s, which is when James Industries began trying new things like the Slinky Dog, the Slinky Train, the Slinky Worm and later the Slinky Crazy Eyes (which were eye glasses with springy eyeballs attached to the lens). They later made plastic versions of the Slinky which were sold in different colors. But Richard left the company that decade and he and Betty got divorced by 1960, leaving Betty in charge of James Industries to try and revive the popularity of the toy, which she was able to do by the 1960s.

In 1962 the musicians Johnny McCullough and Homer Fesperman and the lyricist Charles Weagly wrote the popular Slinky jingle you may remember hearing during the TV commercials. That song became one of the longest-running jingles in advertisement history, and like many commercial jingles I heard as a child, it has never left my head (“It rolls down stairs, alone or in pairs, it makes a clinkity sound! A thing, a thing, a wonderful thing! Everyone loves a slinky.”)

By the 1990s, less popular early versions like the Slinky Dog were discontinued, although after Pixar’s Toy Story came out in 1995 and the character Slinky Dog (Jim Varney) was introduced, that film’s popularity obviously led to a renewed interest in the toy. Even Betty James liked Pixar’s design for the Slinky Dog more than James Industries’ original 1952 version.

By the year 2000, the Slinky received the ultimate honor by being inducted into the National Toy Hall of Fame alongside such classics as the jump rope and the yo-yo. But while kids obviously love Slinky, it’s not only popular as a toy. It’s used as a tool for classrooms (which makes sense because it’s actually a great teaching device for the laws of physics) and it has been used as a mechanical part for certain electronics, including as a radio antenna during the Vietnam War. Some people even use them for artistic purposes, such as sound effects and musical instrumentation. But even as a simple spring that can use gravity and momentum to aid itself down a flight of stairs from one end to the other, it manages to amaze people. The song was right! Everyone loves a Slinky!