While Schmitz is not an obvious imitator of other writers, his tendency to write "series" stories, later novelized into The Universe Against Her and its sequels, follows a pattern set by another prominent science fiction writer, Robert Heinlein. Much of Heinlein's work, which like Schmitz's includes short stories, novelettes, juvenile fiction, and short adventure novels, can be organized into what has been called a "future history." That is to say, his stories all take place in different historical eras in the same future galaxy of Heinlein's invention and are historically consistent with each other. Much of Schmitz's work deals with the Federation of the Hub, a vast alliance of largely human-inhabited worlds whose political and defense affairs are coordinated but not strictly controlled by an "Overgovernment," a power which Hub citizens almost forget is there because it does its job quietly and with a light touch...