I think the "NA" for US-based banks stands for "National Association". Something like that. That doesn't indicate anything about the footprint of a given bank's branches, just that it is chartered under certain federal rules I believe (like in the old days the "First National Bank of" XYZ town, which only had one branch, but has national in the name). The alternative would be some kind of state chartered bank instead.
Besides, MBNA tells me to write check to "MBNA America". I'd like to think that the A is not redundant.

(It wouldn't be the first time if it was, though. When banks started shortening their names, I saw this all the time. FCNB Bank, for instance, where the B is most definitely redundant. And of course, there's always your favorite "ATM machine". Groan.)
Ah, but in reading one page on the MBNA site, it says "MBNA Corporation is a bank holding company and the parent of MBNA America Bank, N.A., a national bank. MBNA America has two principal subsidiaries: MBNA Europe Bank Limited and MBNA Canada Bank, fully chartered banks that issue credit cards in the United Kingdom, Ireland, Spain, and Canada." Somewhere in there is most definitely some redundancy. Oh, well. I still think the NA is probably "N.A.", which indicates a national bank. What the MB once was has been abolished from their history it seems.
Hm, Hoover's has a little bit of history, but not a lot of light to shed on the name:
http://premium.hoovers.com/subscribe...tml?COID=12449 (Strange, it looks like that's supposed to be a subscriber-only page, but I was able to get through to it by first following a link from Google. Dunno. May or may not work.) "MBNA was started in Newark, Delaware, in 1982 by Charles Cawley as the credit card subsidiary of Baltimore-based MNC Financial." More letters! I believe MNC Financial was originally Maryland National Bank. (PNC here in Pittsburgh has a similar history, changing from Pittsburgh National Bank.) So the M might actually stand for Maryland.