To understand how the 1864 battles around Atlanta changed history, it helps to know about the city on the eve of war.

Founded just 23 years earlier and located in the backcountry environs of North Georgia, Atlanta was closer to a frontier town than a bustling city. Its growth was fueled primarily by the junction of four railroad lines -- the Western & Atlantic, the Georgia Railroad, the Atlanta & West Point, and the Macon & Western -- that connected Georgia’s products and merchants to markets westward.

Yet three things were about to propel the town of less than 10,000 into history's path: the confluence of those railroads, a unique entrepreneurial spirit among its inhabitants, and the American Civil War.