Why are so many towns in the US named after Old World cities? Wouldn’t it have confused settlers?

by Cacotopianist

For example:

Berlin (Massachusetts/Wisconsin/New York/Georgia/Pennsylvania/Vermont/Connecticut)
Cairo (Illinois/Ohio/Georgia)
Vienna (Illinois/Indiana/Missouri/New York/Virginia)
Shanghai (West Virginia/Illinois)
Prague (Minnesota/Oklahoma)
Copenhagen (New York)
Paris (Arkansas/Maine/Missouri/Illinois/Tennessee/Texas)
Athens (Georgia/Ohio)

As follow -up questions, why do so many of these towns tend to be in Illinois? And how did random towns in West Virginia and Illinois come to be named after Shanghai, of all places?