Part fantasy, part romance, Somewhere in Time by Richard Matheson is a time travel novel featuring Richard Collier, who falls in love with a turn of the century actress and travels back in time to meet her.
In 1971, Richard, on finding out that he is suffering from terminal cancer, embarks on a road trip from Los Angeles to Denver. On the way, he stops at a historic hotel on the coast in San Diego where he sees a play program from the late 1800s and falls in love with the woman pictured on the front. Captivated by her beauty, Collier researches the actress, Elise McKenna and finds out that she never married, had an overbearing manager named W.F. Robinson, and that she had a brief encounter in 1896 with a mysterious man at the hotel he is currently staying at. Throughout his research, he realizes that he has fallen deeply in love with the woman, and convinces himself that he is the mysterious man with whom Elise had an affair.