A child born across the river from Cincinnati in 1860 would grow up to invent the original subgun, the Thompson submachine gun. He was born in Southgate House, a hopping music venue and bar in Newport Ky. Check out the NKYTribune.com story.
The submachine gun was invented in the ashes of the First World War, and came to late to revolutionize warfare. For close in work, whether the jungles or WW2 cityscapes, the Tommy Gun beat longer range rifles hands down. British Commandoes couldn't get enough of them, and during continental raids, the .45 caliber lump of lead would usually settle things.
The gun was not an overnight success though, most conservative militaries were drawing down after the Great War and didn't have budgets that would include innovative weapons. In desperation, submachine guns like Thompson's would be marketed to farmers for pest control.
In the 20's and 30's, gangsters did take to them, and the police had to respond in kind. During that time period, there were a number of shoot outs with machine guns around the Cincinnati area. Newport was a big mob town through the '50's and 60's. The last shootout in which Cincinnati Police armed with Thompsons was 1957 with safecrackers in Anderson Township, a local sleepy suburb.
Even during the Vietnam War, the CIA carried Thompson's. They are a bit heavy, but they are every bit as useful today as they were in the past.