Why do people think that because I'm "ethnic" my family is not American?

[JenYA]

I'm 4th generation American with Japanese descent, and people always ASSUME my parents are not American (without meeting them). I'm 19 and I have Chinese-American friends my age whose families have just come to America, so I can understand why maybe they'd think I was also 1st generation American. But I don't know whether to feel offended that other people assume my family is foreign just because we're "ethnic". No one in my family has a Japanese accent, and my grandfathers and uncles fought in the US army during WWII. My great-grandparents and many other Japanese-American citizens have worked very hard to be accepted in this country, and it's sad to think that 60 years later, their great-grandchildren have to deal with the same problems.

Don't get me wrong. I am very proud of my Japanese heritage, but I am also American, and I hate that people seem to overlook that.