Penn State’s 162-year history is filled with stories of successful alumni. A quick google search yields an extensive list of notable graduates that includes famous actor Keegan-Micheal Key, former presidential candidate Rick Santorum, and dozens of professional athletes.

But this list, despite its length, is somewhat incomplete. It fails to mention the engineer and 1939 Penn State graduate Richard T. James, who invented one of the bestselling toys of all time, the Slinky, in 1943.

James’s creative epiphany came in the middle of World War II as he developed stabilizing technology for Navy ships in Philadelphia. While working at Cramp Shipyard, James reportedly knocked a sample of torsion springs off a shelf and watched them turn over themselves with signature Slinky-like undulation as they hit the floor.

Intrigued, James and two colleagues, Dylan Gedig and Coleman Barber, developed plans to turn the strangely-moving spring into a children’s toy with the help of a $500 loan. According to the Atlantic, James then spent about two years testing different spring lengths and metals in order to find the perfect combination that eventually produced the familiar, fluid coil.

The toy itself is straightforward but scientifically complicated. Gravity and the weight of the springs work together to simultaneously lift and push down its separate coils, allowing it to flip over itself and move, for example, down a flight of stairs, as explained by a New York Times brief about the toy.

James’s wife Betty, a fellow Penn State student born in Altoona, was instrumental in naming and developing her husband’s idea. According to The New York Times, she settled on ‘Slinky,’ a Swedish word, after scouring the dictionary for a term that captured the sound and movement of the device.

In the annual pre-Christmas shopping frenzy of 1945, the couple sold their first 400 Slinkys in less than two hours  at Philadelphia’s Gimbals department store. The Jameses founded James Spring & Wire Company that same year in order to keep up with the growing demand for their new product. A larger company, James Industries, was founded a decade later. New products included the famous Slinky Dog, a version of which was featured in Pixar’s Toy Story according to Betty James’s New York Times obituary.

But initial success was short-lived for the creators of the Slinky empire. By the late 50s, the company’s business model was failing. Richard James grew restless, possibly because of the influx of income provided by his product and the slight fame it afforded him. His marriage was also in turmoil. He became increasingly involved with a reportedly suspicious evangelical Christian organization according to South Carolina’s virtual library database.

He then decided to move to Bolivia to join what his wife considered to be a religious cult in 1960 according to a 1995 New York Times interview. She refused to accompany him, and remained in Pennsylvania with the couple’s six children. He died in 1974 of a heart attack.

Betty James became the company’s primary leader, and after repairing the damage caused by her husband’s careless spending, brought the business back to prosperity in her hometown of Hollidaysburg. Her almost 40-year stint as president of James Industries spanned from 1960-1998, when she sold the company to Poof Products of Michigan. The Slinky gradually evolved over the course of her time in charge, boosted by a jingle and ad campaign as well as the diversification of the company’s product line. She died at 90.

Over 300 million Slinkys have been sold to date, and the toy has received numerous honors. It’s the official state toy of Pennsylvania, was inducted into the National Toy Hall of Fame and is included in several ‘best toys of the 20th century’ lists from various news outlets.

Betty James accumulated several accolades for her work with James industries. She is a member of the Toy Industry Hall of Fame, and was recognized for her achievements as a female business leader by several organizations and publications.

Today, the Slinky remains a staple of the toy store, and currently costs between four and five dollars.