Regular readers of this column know I'm a student of history. I read about historical things in my leisure, and I studied it in school. I use history to inform my sf and fantasy writing. I use history to craft historical fiction.
Until I started writing my Smokey Dalton mystery series, I did not use primary sources to write fiction. Primary sources, for the non-historians, are the sources composed at the time of the event (and shortly thereafter): everything from all forms of journalism to novels and paintings and letters. Historians in the future will track the surviving . . .