Seventy-four McKinsey Summer Associates walked Gettysburg with Heroes' Path. The minute made Chamberlain famous. The two years made the minute.

Meade had command for three days before Gettysburg. John contrasts his adaptive approach with Lee's fixed plan and what it means for leaders.

Ordered to hold at any cost at Gettysburg, the 16th Maine tore up its flag rather than surrender it. John on its colonel, Charles Tilden.

Brady at the McPherson farm, dead horses at the Trostle barn, a staged sharpshooter at Devil's Den. John pairs Gettysburg's battle photos with the same views today.

In 1938, Union and Confederate veterans met again at Gettysburg. Some children who watched are still alive. We're two handshakes from the battle.

The 11th Pennsylvania's bull terrier was found guarding their dead on Oak Ridge after Gettysburg. Her bronze likeness still lies there.

On the third day at Gettysburg, Lee sent about 13,000 men across open ground at the Union center. Hour by hour, John walks through Pickett's Charge.