A good example of what you're looking for might be the city of Winchester, Virginia.

It was an operationally important city right at the end of the Shenandoah Valley, which Union commanders thought could be an easy route for Confederate troops to march on Washington. It didn't ever end up happening exactly like that, but nevertheless, Winchester was hotly contested and may have changed hands as many as 72 times during the war.

I just linked to Wikipedia because the only source I have is notes from a university lecture the other day. The stuff on Wikipedia seems to corroborate it, for what it's worth. Hope that does it for you and isn't against the rules or anything!