GETTYSBURG, Pa. –  Gettysburg changed the direction of American history 150 years ago, and the town hasn't been the same since.

The couple of hundred thousand visitors expected at events to mark the anniversary of the 1863 clash won't have to look far to find remnants of the pivotal campaign of the Civil War, even outside the grounds of the meticulously maintained national park.

Cannonballs and shrapnel remain embedded in a few of the roughly 200 buildings that remain from the period.

Many of the businesses in the rural county seat cater to the throngs of tourists that stream into one of the country's most historic places, from General Pickett's Buffet to Abraham's Lady, a battle-era clothing shop....