"The Crucible" is historic fiction, which means it's based on real events, but well, some of it isn't. You shouldn't expect it to be a factual account. While some of the details (for example, the number of people who were hanged ) are accurate, Miller used his imagination to create a riveting story and flesh out the characters. Please note that as far as we know, the affair between Abigail and Proctor did not actually take place.
Fun fact #1: I grew up in Salem, MA, where local history was a major part of the curriculum.
Fun fact #2: I attended the University of Michigan, also Arthur Miller's alma mater.