On the Missouri side of the state line in the Kansas City area in the twentieth century, a trip to the downtown urban core of multi story buildings was refered to as “going down-town”. Those on the Kansas side of the state line in the same metropolitan area used the term “going over-town” for the same meaning. You could tell where someone grew up by the usage of this expression.
The distinction, not understood to those of us growing up in the last half of that century had to do with an incline section of rail hooked to the streetcar line that connected the streetcars in Kansas City, Kansas to the streetcars in Kansas City, Missouri. As it crossed the mouth of the Kansas (Kaw) River where it joined the Missouri River it also climbed a steep bluff.
The incline disappeared in 1940 but the expression endured amongst adults untill the 1980s.
My point being, there are often temporary historical origins to these expressions, terms, or usages that get lost or lightly recorded and baffle us later. There were plenty of people like my great-grandfather called “the Dutchman” even though they were of german ancestry, because we waged two wars with Germany — I thought I had Dutch ancestry until I was 25.
The Pennsylvania Dutch, or Amish people, are actually of German descent. Calling German-Americans "Dutch" came from the German word for "German" -- "Deutch", pronounced "doyitch."