Believe it or not, there is a website dedicated to Springfield and Central Illinois' famous Horseshoe Sandwich.
Check it out at www.horseshoesandwich.com.
This past August, the day after visiting the Illinois State Fair, we went to Norb Andy's which says it has the original sauce as served at the Leland Hotel that was located across the street from it. Mighty fine eating.
But, the fact is you can get a great horseshoe sandwich (and even one for breakfast) at most places around Springfield. For sheer variety, get into D'Arcy's Pint.
Bad For You, But Oh So Good. --RoadDog