First, the American county that immediately came to my mind was Harlan County in Kentucky, where 'there are no neutrals there'! And 'sweet Betsy' came from Pike -- Pike County, that is, in Ohio. As has been noted, back when many American folk songs originated, a large part of the population lived in areas that were out in the country, and that meant that that they would identify themselves by there county for want of a city, town or even village designation.

Second, there seems to have been a general oversight of the fact that 'county' has two distinct meanings in America and the British Isles, because we in the US have States. Other that the traditional provinces in Ireland, based on the early kingdoms, and some general geographic areas in Scotland (Highlands and Lowlands) and Englnd (the Midlands, the Downs, etc.), counties have the real equvalance to our states. We certainly have the same strong identities and rivalries (especially among sports teams and state universities) as the counties of Ireland and GB.

Third, many of the hierarchies among English counties date from their histotrical antecedents, such as the War of the Roses and the like. Those areas that were royal dukedoms clearly 'lorded' it over those that were baronies or earldoms. The chauvinism now derives from what was real patriotism then.

I'm from Westchester County myself (in NY) and though I live in the City of Yonkers I associate myself largely with the Town of Eastchester and its nearby Village of Tuckahoe, but I get my mail through the Post Office in the Village of Bronxville, which determines my address. In the old days, I'd probably have though of myself as a 'York Stater'. Now when asked, I usually say I'm from NY.

NY does offer its motorists the opportunity to purchase vanity license plates in many categories and designs (anything to catch the pennies) and amazingly to me, many do buy ones that brand them for all to see as coming from Westchester and other counties, but come to think of it, I've never seen one from The Bronx.

Last thought: New York City comprises five (5) counties!