Your 1963 novel is historical fiction if the story’s events depend on the time period. If the story could just as easily take place in another time period, then it’s general fiction. The historical fiction label gets tricky with modern time periods—especially the 80s and 90s. Reviewers call Eleanor Henderson’s Ten Thousand Saints historical fiction, but the Library of Congress catalogs it as “domestic fiction.” The 80s time period is important to Henderson’s story, but the primary focus is on the protagonist’s drug dependency. Deborah Wile’s Countdown: The Sixties Trilogy, which is as much about 60s America as it is about 11-year-old Franny, is historical fiction.