With no specific academic preparation, I was fortunate to be able to have a career in historic preservation, administering a state historic preservation office for three decades, and serving on the National Historic Landmarks Committee for ten years (four years as the chair while also serving on the Advisory Board for the National Park System). I had degrees in history and anthropology, but I did not prepare myself for work in preservation.

I hired a lot of people over the years, but I did not hire anyone with a history degree or with a degree in public history - because without exception, they were not prepared to do the work that needed to be done - namely evaluate and describe historic resources and assist with the management of those resources. Students with a background in architectural history or archaeology consistently offered more skills that my agency needed.

If I were to advise someone interested in historic preservation and determined to get a degree in history, I would recommend at least a minor in archaeology - with field experience in a historical archaeology excavation. If possible, get some training in architectural history (a minor in architectural history would be a great alternative). A masters degree is also a fundamental requirement given the competition. To give yourself the maximum flexibility in the job market, I would consider taking at least a class in museology - in case you have the opportunity for employment with a museum.

I hope that helps. Ask questions if you need more information.

edit: I also recommend an internship at your local preservation office - local or state.