Glad you asked. And assuming you're actually NOT Mrs. Bouquet/Bucket as your avatar shows, and as an expert jockstrap wearer and aficionado (Or perhaps "Aficia-NADS-oh!") I'll tell you that jockstraps were the norm in America until perhaps as late as the 90's. I base that on experience but also on the superb set of secret lockerroom videos that a guy names Somebody Franck took and which you can find if you goole "Straight off the Mat Franco." They're real dudes in real lorckerrooms and thankfully there are still jockstraps a-plenty. However, in the 90's (and perhaps earlier) compression shorts (ugh) took over and the jock has been in decline ever since. Plenty of articles on the internet attest to their decline. It's too bad really. For guys of my generation it was a rite of passage, a mark of manhood to wear your jocks. Comp shorts suck anyway. Whoever decided they were anywhere close to providing the support of a jock was fooling himself. However, younger guys in America now consider them odd (and to be honest, as one teammate of mine said, "What's so athletic about having your ass hanging out?") and often gay.
I know that in the UK they're not common, and truth be told, sports briefs are just as good. To me, tho, and even tho' I'm not really interested in ass, they remain the icon of masculinity.