One of the most widely used technologies in retail is now 70. On this day in 1952, a patent was granted for the optically scanned barcode. It’s now universally recognized as a series of vertical lines, but was originally designed as concentric circles.

Inventors Bernard Silver and Norman Joseph Woodland came up with the idea for the code. Woodland was inspired by the Morse code he’d learned as a Boy Scout.

“So he experimented with, you know, was it possible to use things like lines and dots and dashes to be able to come up with a two-dimensional code,” said Jamie Martin, corporate archivist for IBM – where Woodland was employed when he was granted the patent.

The company then developed a system using a laser that could read the barcodes. It was more than two decades before it was used in a store. 

“And the first product that was swiped was a pack of Wrigley’s Juicy Fruit chewing gum,” Martin said.

The barcode caught on, said Mark Cohen of Columbia Business School, because it was simple, cheap, and “it dramatically influenced the ability of retailers to understand what it was they sold, and therefore what it was they had left on their shelves yet to sell.”

It’s now a tool used to manage inventory in other industries too, like libraries.