Cavalryman Books 1 through 3 trace the life of an Irish immigrant who, by the outbreak of the American Civil War, becomes a trained horseman. Following a failed romance, he joins the Union cavalry and fights in most major eastern engagements. Book 2 ends with Gettysburg; Book 3 with the surrender of the South. Books 4 and 5 follow the main character into wars against Plains Indians. Book 5 ends with Custer at the Little Bighorn. The series is historical fiction, written by a historian, with an eye to facts and plausibility, as well as entertainment.