Many history students do become teachers at the secondary and post-secondary levels, but there are also many other opportunities for the holder of an history degree.
History traditionally has been a sound springboard to law school; law courses presuppose a certain knowledge of the past and lawyers need to be effective researchers, organizers, writers, and speakers, qualities that history students generally acquire.
Historians also become good writers through the sheer necessity of communicating large amounts of information. This makes them good at disciplines which involve writing, such as journalism. However, along with their writing skills, they are good researchers. Journalism involves much more than regurgitating events; backup research is often necessary.
There are many other possibilities, such as careers with museums, archives, and libraries. There are also opportunities for multilingual historians in government positions and with large multinational corporations. In fact, one can enter just about any field of work with an history degree.