It s an interesting concept definitely I ve never filled out a census before but I wonder how the question is worded when asking about ancestry To me American ancestry means Native American or relation to the peoples of America prior to European discovery Are people making mistakes in filling it out or answering it in a way not intended by the Census Bureau or is this a legitimate option for answering this question In reading the lead to the culture section it does seem that race is a better word to use though I don t say that because American ethnicity exists I say that because America as a nation has no one race and there is no American race North America may have or better phrased had races but once you put political boundaries on the map and consider only the United States then no we don t have a race We do have at least some sort of ethnicity though I m not sure it s worth rewording the section just to include a link to that article