Google has a nifty doodle today for Gideon Sundback, the inventor of the zipper. Today would be his 132nd birthday.
Google Patents has, of course, posted his patent for a separable fastener.
And here’s an IBN post that explains how zippers work: How the Gideon Sundback Zipper works
Zippers are so helpful, even if they are a pain to insert into clothing. Zippers and set-in sleeves are two of the most aggravating things I’ve had to deal with in my sewing.