I grew up on historical fiction. I was reading the American Girl books and Dear America in elementary school. The Royal Diaries connected me with Anastasia and taught me how similar I was to these historical women and how power does not equal safety. Ann Rinaldi’s novels were some of the first I read which featured protagonists of color. Bustle highlighted Rinaldi’s work as a feminist author, if you want to read more about her stories.
While fantasy and science fiction made me long for adventure in another world, historical fiction grounded me. I saw the adventure in our world, even if it was set in another time or another country. Historical fiction provided me with my first realization that there have always been incredible historical women–even if our history text books omit their names and actions. It’s no wonder that I became a creative writing and history double major in college.
I used to go into bookstores and ask for the historical fiction section only to be told it didn’t exist and to look in the General Fiction or Literature section instead. Historical fiction has gained honorary literary fiction status, in some cases even becoming classic works. Consider Margaret Mitchell’s Gone with the Wind (published in 1936, set during the American Civil War) or Colleen McCullough’s The Thorn Birds (published in 1977, set between 1915-1969).
I’ve been trying to claim historical fiction as speculative fiction for years now–it’s not set in our time, how can it still be considered literary fiction?? But I think I’ve finally re-evaluated my classification. Historical fiction isn’t speculative fiction, but it has the easy potential to be.
There’s nothing more speculative to historical fiction than a literary story or novel. (I’m defining literary fiction as a story set in our world/our time–or close to our time.) Everything in a historical fiction novel could (or did) happen. What exactly are we speculating about again? 
But the lines can become blurred. Connie Willis’ novel Doomsday Book is both historical fiction and science fiction. Heavily researched to understand all the cultural norms of English life in the 1300s, the novel is also a time travel adventure with the plot split between the past and the future (check out all the novels set in her time-traveling historians series–yes, Connie Willis is that cool to have invented this use for time travel). Also, consider Diana Gabaldon’s Outlander Series. Again, historical fiction and science fiction (and romance). Willis and Gabaldon wrote highly acclaimed series, which are respected in popular and literary circles. The Outlander books have been adapted into a TV show. I first read Doomsday Book for a literature class in college.
I can’t claim historical fiction as speculative fiction (no matter how hard I’ve tried). But the genre is rife with pieces that toe the line. Alternative history. Time travel. And like speculative fiction, what is historical fiction, but another way to re-imagine the world?