(Dr Q) In one of the jazz pubs I go to is a vast mural with a map of the lower Mississippi and New Orleans and there is a place on the river called D'Lo (presumably at one time De l'eau). We don't take anglicisation quite that far because we've got places such as Grosmont (N. Yorks) and Grosvenor (London) in which the "s" is silent, even though the names are several hundred years old. (Bigsmith) Yes, why, particuarly as Berkhampstead is BURK, but not Berkeley Square. Re Shrewsbury - two locals I have known call it Shrooze, for what it's worth.
Towns in America often have names reflecting the language its settlers spoke, or occasionally that of the natives who previously occupied the area. Mind you, these don't quite explain some towns just East of Lancaster, PA....
In Saltfleet, Linconshire, there is a Paradise Car Park, with a sign reading Paradise Car Park, No Caravans or Camping. It's unpaved, but it's a parking lot all the same.
[Rosie] Yes, we can blame the French for dropped "w", silent "s" and all kind of manglings. I say "Shroozebury", btw, but then I also say "Sisister" for "Cirencester", and I may well be wrong about that. I also insist on "Alster" for "Alcester", despite the tendency of south Brummies towards voicing every letter in the name of the main road that I live just off. Bah!
I thought it was pronounced Shrooze-brie, but it seems to be more variable than that. Near me is Caerphilly, pronouced Ku-philly, but then all the Welsh names starting Caer seem to be pronounced like that, eg Caerleon. It took me ages to get them right, and it's probably different in North Wales. I also remember a sea-side village in Fife, on the Forth, called Ainstruther, pronounced Ainster. It's really a plot to make fun of tourists!