As cliche as it sounds, you need to do what makes you happy or at least professionally fulfilled. It also depends on the level of your degree. I'm going to assume you're getting your bachelor's because I can't imagine going to grad school and still being unsure of the field I want to enter.

Formal Teaching: teaching middle/high school should really only be considered if you want to do it, not if you're doing it because its the only thing you can think of. Check with your state's certification board to see what is required.

Informal Teaching: working at a museum or other educational location can be a great way to use your knowledge of a certain topic.

Journalism: A History degree teaches you how to research and write. While the jobs are disappearing, news media has scooped up more than a few historians as reporters and journalists.

Non-related: As shitty as it can sound, many employers don't care what kind of degree you have. Many times you can make more money selling insurance or working at a mid-sized paper distribution company than teaching or working at an historical site. Again, do what makes you happy.

Keep going: again, assuming you're working on a bachelor's, consider continuing your education. If you decide history isn't your thing, you can always get an MBA or other non-history related Masters or PhD/MD/JD. I know several people who have B.A.'s in history that are medical doctors, lawyers, etc.

The bottom line is that a degree is just a piece of paper. Its what you do with it that matters.

Think about what a history degree teaches you on a fundamental level.

It teaches you to look for facts to back up a point and then how to explain it.

You can take this a few ways.

Research: Finding data on an issue and creating reports

Marketing: Finding the data on consumers to market a product or if a advertising campaign is working.

Data Analysis: Creating databases by researching topics.

Really its what other experience you have that allows you to use that degree.