Are these neighbors or concentric circles, with steampunk in the bulls-eye?
First and foremost of the above I am a science fiction fan and writer. It wasn't until a conversation with a friend acquainted me with the term, steampunk, that I realized my first novel might fit within the genre. Since then I've thoroughly enjoyed meeting the marvelous ambassadors of steam at conventions and wherever else my travels find me. The alternate history label fits too, but loosely. I like to consider Adventures Above the Aether and its new sequel, Aether Legion, not so much alternate but hidden history.
Many works of fiction, especially science fiction, works to weave stories into our past that offer thrilling explanations for history's stranger twists;. Wild Wild West, X Files, Warehouse 13, and Dr. Who to name a few. None of these offer a divergent history so much as stories too bizarre or too dangerous to make it into history books.
Adventures Above the Aether tells the tale of a discovery made slightly earlier than history reveals. With their 'aetherphone' my characters learn of other worlds and with that impetus they venture farther than any recorded expedition of the time. In the end they realize an important reason to keep their travels and developments secret.
So is it science fiction? Yes. Is it alternate history? Yes. Is it steampunk? While I don't have nearly the number of gears and gadgets I see at the conventions I attend, I offer a resounding yes.