Depends how far you wanna go back - I'm guessing most of the people posting English / Italian / French etc. above are American. Can I ask you all an honest question - how can you be sure that (for example) your Italian mama's mama wasn't of part Scottish, part Swedish, part Whatever extraction and just settled into the Italian way of doing things when she married into Italian grandpapa's family? Are you all geneology enthusiasts? And what's wrong with being a white American - if all the Germans I know can happily and proudly say 'we are German' and 'the Nazi's were a shower of evil fuckers' in the same breath why can't you all just be white Americans? This is something that has always confused me - why the need to connect to an 'old country' when you have a perfectly good country of your own (or at least you will have again, hopefully, come January 2009)
Anyway, I'm white, nationality Irish - my ancestors were:
1900 to present - mainly Irish, one English
1800 to 1900 - Scottish, Irish, English, Dutch
1600 to 1800 - French, Scottish, Irish, Dutch, English
1100 to 1600 - Norman, French, Scottish, Irish, Dutch, German, Spanish
pre 1100 - unknown