As much as Americans love hot dogs, it is possible to get too much of a good thing. One can probably guess how quickly hot dog vendors themselves can get sick of them. That's what happened to hot dog vendors (and brothers), Harry and Pat Olivieri.
The brothers ran a stand selling hot dogs in the 1930s. The story goes that Harry concocted the original steak sandwich one day for Pat when he was working the stand and couldn't make it home for dinner. Harry brought him some steak and a loaf of italian bread. When a cab driver, equally sick of hot dogs, saw what the Olivieri brothers were eating, he wanted one for himself and offered to buy it.
The brothers became successful selling what was called at the time "steak-wit" -- short for steak with onions. Because so many customers were Jewish and ate Kosher, the brothers didn't introduce cheese in their sandwiches until later (melting it separately before pouring it on for customers who wanted it) [source: NPR].
Today, the restaurant they started, Pat's King of Steaks in Philadelphia, is still very successful, despite fierce competition right across the street. In 1966, Joe Vento opened a rival cheesesteak shop, Geno's Steaks, across the street, whose die-hard patrons say is better and cleaner.