look at the hoeflertypefoundry.
at www.typography.com

or at the typeface 'federal' or 'zapata' at
www.letterror.com

the hoefler has some old revived sans-serif's and the boys of letterror have made two beautiful persiflage on american-western typography in the form of 'zapata' and 'federal'

succes

I agree with Jonathan. Living in the midwest, and seeing many old school signs, the most typical face would be the sans serif set in all caps.

If your interest is early 1900s midwest display typography (à la signage), then you may want to try contacting John Downer (he'll be at TypeCon in Toronto next weekend). He's an accomplished sign painter, as well as a type designer, from Iowa -- you can't get much more midwest than that, I suppose -- and he's a collector and aficionado of public display lettering from this era. I'll bet he could offer expert advice.

Thank you all so much for your kind assistance. I am on the path now...

Knockout, Gotham (caps only), and Gotham Condensed might be good choices from among our collection at typography.com, unless you're a stickler for absolute historical accuracy. That is, these faces can easily engender a Dust Bowl feeling if used appropriately, but strictly speaking they're all new designs from 2000.

If you're going for museum-piece accuracy, look for typefaces issued by the Ludlow or Barnhart Brothers & Spindler type foundries -- you can probably do some sleuthing at myfonts.com. But to get you started, try Tempo, Cheltenham, Franklin Gothic (not ITC), Cooper Black, Alternate Gothic, Post Roman, Copperplate, Radiant, Agency Gothic, Poster Gothic, Bank Gothic, or the ineluctable Goudy Old Style. As always in typography, finding the right font is only half the battle -- the real challenge comes in composing them properly.

JH