Most people have been exposed to the highlights of atomic theory. But even chemists and physicists who have taken courses from modern text books only see the tip of the iceberg. Indeed, I believe that the textbooks themselves often distort the story. Here I have tried to bring a higher level of detail and avoid some of the popular misconceptions about atomic theory and the people who developed it. I think that these details assist in the understanding of the theory and the process of scientific discovery. The book begins in 1800 and essentially ends in 1950. Beyond 1950, the developments in particle physics are actually a different activity than study of the atom per se and I have some doubts that the models of subatomic particles that have been produced over the last 50 years will stand the test of time. In particular, I find the history of the neutrino to be something of a distraction and mystery. I have written about this issue before and provide an appendix that raises my concerns.