The HUxley family were famous (or infamous) British atheists. In fact, it actually got to be such a family tradition that it turned into a quasi-religious ferver, handed down through the generations.
I guess “famous” is relative, but Dawkins and Hitchens were quite famous long before The God Delusion and God Is Not Great, for their work on biology and politics (respectively).
Some people may have called the Huxley’s atheists, but they called themselves agnostics. At any rate, T.H. Huxley, the founder of the clan, did (I think he actually coined the word “agnostic”).
I don’t really understand the argument you are trying to make from your description in the OP, however.
If you’re looking for people who aren’t famous for being atheists and who you may not even know are atheists, there are plenty. Lance Armstrong for one.
Thomas Paine is often called an atheist, but in The Age of Reason he specifically denies being one, and give the organization of the solar system as an example of how a creative intelligence is required to explain the world. We was definitely not a believer in the Judeo-Christian God, and neither was Jefferson. I suspect Jefferson would have been close to Paine in this . If Paine were alive today, and knew the findings of science, I’m sure he would be an atheist, but he wasn’t then.
Though it should be remember that at the time Atheism was a crime (under Blasphemy law), so he is unlikely to admit to it.
Albert Einstein. Even though a lot of Christians have tried to lay claim to him through some contextless quotes, the man remains more atheist than religionist