The highlight of the observance will come on Sunday, when 10,000 Civil War re-enacters will take part in a recreation of the battle. They will have paid their own way, provided their own props and uniforms, and fought the battle using the same tactics used by the combatants at the time. They will pray for cool weather given that their wool uniforms are incredibly uncomfortable. And many of them will probably weep, overcome with emotion during the re-enactment, as many of the 13,000 re-enactors wept during the filming of Pickett’s Charge in Gettysburg.

Visitors — even those who know a little something of what transpired on those few square miles of ground — will tour the grounds as if it were a religious shrine. Speaking in hushed tones, sober, somber Americans will read the plaques, listen to the hugely knowledgeable park service employees as they relate interesting tidbits about the battle, and marvel at the courage demonstrated during the most famous battle in American history where the two sides came to death grips at a stone wall at the crest of a gently rolling hill known as Cemetery Ridge.

You ask yourself, “Could I have done what they did?” Could you have marched across the bloodiest 8/10 of a mile in America as Pickett’s men did? Could you have stood your ground while 12,000 screaming rebels were coming right for you? Trying to answer those questions tells us a lot about ourselves as individuals and Americans.

In John Keegan’s Fields of Battle: The Wars for North America, the author takes us on a journey into the distant past to fortresses and battlefields where once desperate men fought desperate actions in forgotten conflicts and where the battlefields have largely been reclaimed by nature. This will never happen with Gettysburg. It isn’t that 51,000 Americans on both sides were killed or wounded, or that it was a turning point in the war. Gettysburg will always be maintained as a living monument to our desire for freedom. It is a symbol of our commitment to liberty — forged in the blood of the Revolution and made flesh by the sacrifice of so many in Pennsylvania.

Perhaps that’s the most important echo from the battle that reaches us 150 years after the guns went silent and the dead were buried.