At the mention of Gettysburg, Jeff Stocker fidgets in his chair.

Stocker, wearing a gold necktie adorned with the likeness of Abraham Lincoln, turns to his left and tilts his head slightly toward the ceiling. A smile emerges from his gray goatee.

Gettysburg looks different, he says. It smells different.

"Oh my God, Gettysburg is ethereal," Stocker exclaims from behind the desk of his Allentown law office. "To be in the field at Gettysburg … it gives me chills just talking about it."

The rolling Adams County farmland, just 10 miles north of the Mason-Dixon line, is where Stocker's great-grandfather wrapped his arms around a wounded Union captain and dragged him from onrushing Rebels.

It's where Stocker retraced the footsteps of both armies on summer days with his father, who wondered aloud what their Civil War ancestor looked like.

And it's the inspiration for part of Stocker's latest book — an in-depth account of Pennsylvania's 153rd Volunteer Regiment, the band of novice soldiers mostly from Northampton County that his great-grandfather joined.

Gettysburg gave Stocker a cherished father-son bond through a beloved battlefield. For the battle's 150th anniversary, which begins July 1, Stocker is giving the Lehigh Valley the story of its ancestors who fought there with the 153rd Pennsylvania infantry.

"We Fought Desperate," which will be released this year, includes a full roster, complete with as many details as Stocker could find about each of the regiment's 993 soldiers.

Over the last seven years, he's traveled back in time, reliving Gettysburg through the letters, diaries and pension files of more than 500 local men who were there — many of whom never made it home.

"The dots on the map are people," said Stocker, of Center Valley. "I hope you realize that this is a real-life person with a real-life family. Chances are, just like you."

A servant in the fight

One of those dots on the map is Heinrich Feirich, a 40-year-old shoemaker from Moore Township.

Feirich's wife was pregnant, but that didn't stop him from volunteering for a nine-month enlistment with the 153rd Pennsylvania in September 1862.

A Prussian immigrant who had yet to become a naturalized American citizen, he was one of 54 men in the 153rd who left behind a pregnant wife or girlfriend.

Only four months into his enlistment, Pvt. Feirich began suffering from deafness in both ears and was reassigned as a servant for Capt. George Young, also of Moore. Feirich did his company's washing and assisted Young.

By late June 1863, Confederate forces under Gen. Robert E. Lee were invading the North. A decisive win could give the Rebels the momentum needed to threaten Washington, D.C., and possibly force peace talks.

As Lee's army plundered the Pennsylvania countryside, the 153rd marched 10 miles over four hours on the morning of July 1 and came to a grassy hilltop on the northeast corner of Gettysburg's battlefield.

Positioned too far from the rest of the 11th Corps, the regiment got hit hard by Confederate troops who charged out of a nearby thicket of trees.

Capt. Young, shot in the face, was among more than 250 from the 153rd wounded, killed or captured as the Confederates trounced the weary regiment.