How about an historic Hot Wiener-athon? Stop at The Original NY System on Smith Street, then hit Olneyville NY System, then head to Sam's on Mineral Spring Avenue. The last one isn't terribly historic, but it is my favorite....and they still have Cabinets on the menu as well I believe, so that's historic.
If you want to go a bit more upscale (which wouldn't be hard), how about doing an app, entree, & dessert each at a different place on Federal Hill? I'd recommend the fried squid at Dolce Vida, entree at Siena, Mediteraneo, or Providence Oyster Bar, then dessert at Pastiche (Banana Creme Pie is outstanding).
Providence Oyster Bar
283 Atwells Ave, Providence, RI 02903