A recent article on this subject.
“During the depression, going back to Upton Sinclair and the old Chicago stockyards, actually when it was made, some of the meats weren’t always good,” Chiappetti said. “So they actually used ketchup on it to cover up, the flavor of bad meat. So it used to be prideful, that we don’t serve ketchup. Meaning our hotdogs were better than everyone else’s."
https://www.nbcchicago.com/only-in-...hot-dogs-the-history-that-started-it/3683702/
Also from the interview with the restaurant owner,
"His restaurant in the Loop often attracts tourists, and many, who request ketchup on their Chicago dog.
“Of course we have to say no!” Chiappetti said. “We say ages 8 and under, you can have ketchup, but we try not to serve it.”
So maybe ask for ketchup, only if it’s for the kids. Otherwise, respect the reason that here in Chicago we skip the sweet red sauce.
“People didn’t want to cover it up and mask the true flavors. And how great is that? What a great premise to eating. Give me the natural, the best, don’t cover things up in sugar. I think the hotdog story is a lot of what the culinary story is in Chicago," Chiappetti said."
So it's official, at least in Chicagoland. So remember fellow BITOG people, including
@GON, when in Chicago, order your hotdog sans ketchup. To do otherwise may be a major faux pas.