Personally I think that Americans believe in Creationism, or some similar belief, because many are still fervent churchgoers who believe the stories of the Bible. The Garden of Eden myth is quite enchanting, all the created things getting on like a house on fire, then it's all ruined by the female, so let's invent original sin and make her pay for it forever! OK I've muddled up at least 2 denominations there, but many Americans do believe in Bible myths. Many more than in other countries. These beliefs are taught in childhood, as they were in Darwin's time, with largely the same result. People who feel the foundations of their faith may be shattered are not going to believe another theory, which has not obtained the appproval of their church. Epecially if they are told that they risk of losing the possibility of Eternal Life for it.

I would have thought it was possible to accept the Theory of Evolution on a scientific basis without it upsetting the religious apple cart, but it appears I am wrong.

Really it doesn't matter in the long run,. Evolution will continue, some people will not believe that it is doing so. Surely there aren't that many. Do they hold up research, stop the 'marrch of progress' or are they just nuisances, or more likely irrelevances, and annoying?