The name of this restaurant describes exactly what they do and exactly what they are. This is a cart with wheels, also known as a wagon. They make and sell hamburgers. That's it, that's the description.
I've been hearing about this spot for years, and it's considered a local classic. They have been in business since the Great Dayton Flood. In fact, they owe their existence to the Great Dayton Flood. I'll let you read about that history on their website, it's a fascinating story. What I am here to tell you about is my experience.
My wife and I headed to Miamisburg on a sweltering summer day around lunch time. There is a steady stream of customers at this spot, it's clearly beloved. Some folks would come up and order 50 hamburgers, clearly planning to take them back to work and feed the entire office. There were only two people inside the wagon on the day we visited. One person handles the cooking. The other person seasons and assembles the burgers with one gloved hand, and handles money with the other hand... these hands never touch each other, the money hand doesn't touch the food, and the food hand doesn't touch the money.
That's right, I said money. Hamburger Wagon only accepts cash.
As for the menu, they make hamburgers. They sell bagged chips. They sell bottled drinks. As a customer, you're getting your own drinks from the cooler and chips from the rack. If you want a cheeseburger, well, too bad. This is Hamburger Wagon, not "Cheeseburger Wagon." By default, the hamburger comes with freshly sliced onion, a pickle, salt, and pepper. If you do not like one or more of these things, you can ask for them to be omitted. You are not getting anything else. You are not getting ketchup, mustard, mayonnaise, aioli, chutney, gochujang, hoisin, ranch, blue cheese, thousand island, barbecue sauce, peanut butter, jelly, lettuce, tomato, bacon, avocado, etc. This is a simple hamburger with freshly sliced onion, pickle, salt, and pepper. It is small. You'll probably want more than one of them.
The hamburgers are cooked in what appears to be a large cast iron receptacle at the back of the wagon, in a great deal of boiling liquid fat. They are coming out all sorts of well done, with some char and crunch around the edges. This is what they do. If you do not like this, do not visit Hamburger Wagon.
I loved my experience. Though simple, the burgers are well seasoned, crunchy, and delicious. It's probably not the healthiest thing to eat every day, but every once in awhile, it makes for a nice lunch. I understand why it's so popular and beloved. They figured out how to do one thing well, and they've done it the same way for over 100 years. Again, it's simple. Good things don't need to be complicated. If you happen to be carnivorous and also in the Dayton area, this is a place you should definitely try at least once.