I've always been curious why there didn't seem to have been as much fighting directly between the two capitals as I would have expected. Were they just insanely fortified? Or did it just never make sense strategically for either side?
I'm a bit confused by your third sentence. Are you suggesting that the area around/between the two capitals did not see much fighting? If so, I really couldn't disagree more. Northern Virginia was the great meatgrinder of the war, a relatively narrow strip of land between mountain and sea where the principal armies of the two republics - the Army of the Potomac and the Army of Northern Virginia - repeatedly clashed for more than three years, inflicting hundreds of thousands of casualties. The largest campaign of the war by number of men involved took place on the outskirts of Richmond - the Peninsula Campaign of 1862. First and Second Manassas/Bull Run, Fredericksburg, Chancellorsville, the Wilderness, Spotsylvania, Cold Harbor, and the Siege of Petersburg were all major battles that took place roughly between the two capitals.
If I haven't answered your question, please feel free to clarify and I'll do my best to oblige.