Condoms in the Twenties

So I want to write a book with the protag in the Twenties. I know condoms were legal in the US, even advertised. But I have no idea where my protag would buy them.

Would it be a mail-order thing?
Would drugstores have them?
If so, would they be out on the shelves like they are today, or would it be something you'd have to ask the druggist for?

Any info would be helpful. Thanks.

Thanks!

The ironic thing is that I've done a great deal of oral history research about growing up in the Twenties and Thirties with my relatives. I've got LOTS of interesting stuff that never made it into history books.

But this just wasn't a topic that ever came up. Not the sort of thing you ask your grandma or great-uncle.

I love the barber shop thing. It's so elegant in comparison to the drug store.

I suppose I could dodge the bullet. The guy's going to be rich, although he'll lose it all in the stock-market crash. But I suppose it's the type of thing people who had valets could pay them to do for them.

I think I'm going to have to put him in New York, where I've never even been. Other than Gatsby, does anyone have any reading recommendations?

ETA: I suppose I could put him in Chicago. But he's a young man from the Midwest who wants to get away from the farm, and either of those seems like a more likely destination than say, Minneapolis or Indianapolis, which are the only two cities I have oral history research info on, other than LA. The last seems unsuitable, although I suppose he could take a Pullman car.