Why the reference to Mexico for what seems to be a fairly major road in Hampstead Maryland? Maryland seems awfully far away from Mexico for any sort of cultural influence.
The small cluster of houses in the vicinity of the intersection of Routes 27 and 482 was historically designated as “Mexico.” I have no idea why. I’m even more astounded that this question about my immediate neighborhood has even arisen – anywhere.
I know the area, between Hampstead and Westminster, but don’t know why it is called Mexico.
Seemingly random placenames show up - Damascus, MD, for instance. 
Do Hampstead and Westminster have any relationship to Hampstead and Westminster?
Huh. I’m all of about 20 minutes up the road from there in PA and I never knew it was called Mexico. For a couple of years I even drove right through there every day on the way to and from work.
Hampstead was settled by English immigrants and was named after Hampstead, England.
Westminster was named after William Winchester, who purchased the land in the early 1700s. The land was originally called it White’s Level as it had been owned by a man named John White who gave the parcel of land its original name. It was later renamed in honor of William Winchester.
I live up the road in Hanover, PA, which was named after Hanover, Germany. Incidentally, Hanover originally got its charter from Lord Baltimore, and was in that strip of land that both PA and MD claimed ownership of, which was eventually settled with the creation of the Mason-Dixon line.
In Carroll County’s (MD) rural past, any cluster of three houses or more had a name. Any of you locals ever hear of Dogtown or Hoods Mill?
I’m even more astounded that this question about my immediate neighborhood has even arisen – anywhere.
A customer gave me his shipping address on Hampstead Mexico road and it jumped out at me as a strange name for a road in Maryland.
How do you get “Westminster” from a “Winchester” surname?
It’s funny how names like that show up in America. Not far from where I lived in Whitehouse, Ohio, you could drive through both Mexico, Ohio (founded in 1832 and named after the Mexican War of Independence), and Texas, Ohio (founded in 1846 and named after newly-admitted Texas). I would bet that Mexico, Maryland is similarly named.
And, in looking it up in Wiki, there are at least THREE places called Mexico, Maryland. Popular name, that!
D’oh! I left out an important part, didn’t I?
It was later renamed Westminster because Winchester was also the name of the county seat of Frederick County. William Winchester was from Westminster, England, originally.
That’s what I get for typing in a hurry.
I know where Dogtown Road is and where Hoods Mill Road is, but I don’t know where the actual locations are.
Completely understandable. I’m just amazed that my little nondescript part of the country is being mentioned at all on this esteemed board.
Thank you. I worked in Westminster, MD a few times. There I was earnestly and clearly incorrectly told, in a lovely folk etymology, that “There were two ministers, and the one to the west is who the town is named after.”
Every one of you is an imposter; you aren’t pronouncing it “Westminister.” 
I would guess it’s named in honor of Mexican independence. It wouldn’t be the only such US place. There’s also several US places named for Simon Bolivar.
There’s lots of US places named because of the Mexican-American War, although I wouldn’t expect this to be among them. For instance, there are two Churubusco in the US: one in NY and one in IN, both named after a battle of that name. And except for the one in California, most (if not all) of the Monterey’s in the US were named for the Battle of Monterrey. However, they’re all spelled with a single R like the one in California, rather than a double R like the one in Mexico.