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A compelling, historically accurate novel that weaves together the overlooked stories of the Union’s 2nd and 3rd cavalry divisions and forever changes the vision of the cavalry’s contribution to the Union victory at Gettysburg. Grounded in the words of the men who persisted, prevailed, and perished in the bloodiest battle of the Civil War, Thundering Courage takes you back in time to the moment when the tide turned toward the redemption of the Republic – and the rise of a 23-year-old national hero. VIEW PROMO » 


Dr. Terry C. Pierce was the Director of the USASFA Center of Innovation, where he championed disruptive innovations for the Federal Government. Previously, he was Associate Dean and research associate professor of Information Sciences at NPS. READ MORE » 

Dr. Terry Pierce in Uniform

Thundering Courage:

George Armstrong Custer, the Union Cavalry Boy Generals, and Justified Defiance at Gettysburg

Now Available


Cover of Thundering Courage by Terry C. Pierce. Thundering Courage: George Armstrong Custer, The Union Boy Generals, and Justified Defiance at Gettysburg

“Promotions or a coffin!” To George Armstrong Custer, war is the Devil’s own fun. And his luck—”Custer Luck”—peaks during the Civil War, keeping him alive against all odds. Yet, for the first two years of the war, Custer luck has not earned him a command—until, three days before a brewing battle at Gettysburg, Captain George Custer is promoted to brigadier general. Possessed with raw courage, rare gallantry, and reckless heroism, Custer becomes the youngest general in the Union army.

Hugely spirited, tactically flexible, and fiercely ambitious, Custer, on July 3, 1863, trots in front of the First Michigan cavalry regiment, grips his sheathed saber, and pulls. The blade swishes from its metal scabbard with the sleekness of a swooping hawk. “Come on, You Wolverines!” he yells. And the 23-year-old leads one of the greatest cavalry charges in the annals of warfare.

Craving attention, approval, and glory, the boy general with long, flowing, golden locks is an impulsive, fearless daredevil. Commanding the Michigan Cavalry Brigade, Custer is throttled by his vainglorious reporting senior and ridiculed by battle-hardened Wolverines. But the pride that lies in the flesh of all men is thicker in Custer. He loves dancing at the edge of death’s doorstep. And he believes that moral courage means leading from the front—but not always following orders. Because he knows that, between orders and duty, blind obedience and justified defiance hang in the balance.

Thundering Courage is the riveting story of the Union cavalry’s Second and Third Divisions at Gettysburg, boy generals who face crises of justified defiance, and the unsung hero who wisely keeps a human thunderbolt on a tight, short string. Built firmly upon the annals of history, Thundering Courage journeys through the hearts and minds of Union cavalry heroes who face the agony of choosing between blind obedience and justified defiance at the Battle of Gettysburg.

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Custer at Hanover by Dale Gallon - www.gallon.com

The front cover of Thundering Courage: George Armstrong Custer, The Union Cavalry Boy Generals, and Justified Defiance at Gettysburg is a painting by Dale Gallon, called Custer at Hanover. Gallon Gallery has given permission for Terry Pierce to use Custer at Hanover as the basis for the novel’s cover.


“Riveting, vivid, fiercely depicted. Thundering Courage is a beautifully crafted novel of authenticity and power tracing the meteoric rise of George Armstrong Custer from the rank of Captain to Brigadier General. The utterly engrossing story provides a remarkable inside view of Custer’s towering personality as an impulsive and fearless daredevil. The battle scenes are brilliantly written, especially the Boy General leading the First Michigan in one the greatest cavalry charges in military history. A Remarkable achievement. Like Custer’s charging Wolverines, the reader is thrust into the story at a gallop, plunging from page to page. The book recreates a pivotal moment in history with extraordinary authority and insight. Thundering Courage is thoroughly compelling – an absolutely gripping read. Truly a great book. “

– James Stavridis, PhD, Admiral, US Navy (Retired), Supreme Allied Commander at NATO, 2009-2013, Dean, The Fletcher School of Law and Diplomacy (2013-2018)

“Until now, generations of Civil War enthusiasts have relied on Bruce Catton, Shelby Foote, and novelists like Michael Shaara and his son Jeff to be our story tellers. And although The Killer Angels brought the human emotions of Lee, Longstreet and Joshua Chamberlain out of the dark, the conflict of East Cavalry Battlefield remained hidden. That pivotal moment that took place three miles east of Gettysburg on the rolling rural fields July 3, 1863, lay yet to be explored. Enter Terry Pierce. Like a bold cavalry charge, he corrects this oversight with his unique insight breathing a fresh new voice to those who stood beside cannon and saved the Union flank at Cress Ridge and Rummel Farm. Terry’s thorough research captures both the nuances of dialogue that’s right on and the minute details even down to how Custer held his pen. This is the book that has been long awaited to be written. When I read the last page and closed the book, I knew Terry Pierce had accomplished and written the Last Word on the cavalry action of July 1863 with style, with impeccable research, correctness and with Thundering Courage.”

– Steve Alexander – “Foremost Living Custer Historian” – portraying Custer

Thundering Courage is the second book in author Terry C. Pierce’s Gettysburg trilogy, building on the story and success of Without Warning. From the very first chapter, he takes you on a wild ride, telling the rest of the story of the Battle of Gettysburg and the rapid, unlikely ascension of one of American history’s most controversial heroes, Boy General – George Armstrong Custer. From its opening pages, Pierce brings to vivid life what it feels like to be in the center of daring cavalry charges again and again.  Along the way the reader is introduced to the nascent signs of Custer’s greatness and the fatal flaws that would ultimately contribute to his eventual downfall at Little Big Horn.  Throughout this exciting and thought-provoking novel, we are introduced to the concept of “Justified Defiance” and are left to ponder whether it is ever acceptable to disobey an order.  It seemed to be for several Union cavalry officers on July 3rd.  I loved Thundering Courage – an epic novel grounded in history and the timeless insights of why commanders should be leaders of character.”

– Steven J. Rauschkolb – Managing Partner, The Crisfield Group, Board of Directors – Civil War Roundtable Congress

Thundering Courage is truly a masterpiece of storytelling.  It is both epic and meticulous in capturing personalities faced with critical decisions and actions while in the chaos of battle. I was totally absorbed by this historically accurate novel. I am sure almost everyone is familiar with George Armstrong Custer’s inglorious last stand at Little Big Horn, but I, for one, was not familiar with Custer’s glorious feats thirteen years before and during the Battle of Gettysburg.

The character-driven story is fast-paced and totally engrossing.  The writing is crisp and vivid, and the dialogs convincingly imagined.  The battle scenes are graphically written, sometimes shocking, but always gripping.  The reader feels as if they are riding with Custer’s Wolverines during his daring cavalry charges.  The novel is a must read for understanding the challenges of command and Justified Defiance.  Superb!”

– Rear Admiral Ronald Christenson USN, retired – former Commander USS Theodore Roosevelt CVN-71

“Terry Pierce breathes life into the Union cavalry leaders at Gettysburg. Their character becomes manifest as the reader experiences their behavior with the backdrop of this great battle.  Thundering Courage details the inner conflict of flawed individuals and is told with clarity and alacrity. I can’t recommend this one more highly!”

– Mike Movius, President, CWRT (Civil War Round Table) Congress

Thundering Courage is a groundbreaking feat of historical fiction revealing the heroic role the Union boy cavalry generals and their troopers played in Gettysburg’s overlooked cavalry battles.  This well researched novel and powerful narrative reveals the challenges and pitfalls of promoting young cavalry Captains to Brigadier Generals three days before the Battle of Gettysburg.  In this page-turning story, Terry Pierce focuses on a youthful George Armstrong Custer and brilliantly captures the whole of Custer’s towering personality as he jumps from Captain to Brigadier General.  Over the next four days, Custer challenges fate and leads three remarkable cavalry charges that skyrocket him to national fame.  The searing accounts of these cavalry battles were nearly impossible to put down.  Thundering Courage brilliantly reveals the flaws of Custer’s passionate yet self-destructive character that will lead to his fate at the Battle of Little Big Horn eleven years later.  Pierce is a skilled writer, with the rare ability to conduct meticulous research and create a captivating story. This gripping novel is a must read and should be on the Commandant’s Reading List along with Terry Pierce’s first novel in his Gettysburg Trilogy Without Warning.”

– General Charles Krulak, USMC, Retired – 31st Commandant of the Marine Corps

“A masterful, detailed, and gripping version of the Union Cavalry’s stunning performance and contributions to the Union’s Victory at Gettysburg. Too often, the reader is given the strategic and operational level perspective with notable examples of some of the tactical events sprinkled throughout the story.  But in Thundering Courage, Dr. Terry Pierce has woven the myriad tactical level events, and the individuals responsible for their execution, into every page of this historical novel…and I couldn’t turn the pages fast enough!  The piece de resistance in the book, is the way Pierce unveils the moral, ethical, and legal dilemmas facing every tactical leader when ordered to execute a task their experience, on-scene knowledge and instincts know will fail…and worse might lead to the loss of the overall battle. Just as senior civilian and military leaders have used Shakespeare’s Henry the V, in various leadership laboratories, those senior leaders of the future might find, among the dozens of well documented cases in Thundering Courage, perfect examples of how leaders at all levels might better coordinate and synchronize their efforts on the battlefield.”

– General Gregory (Speedy) Martin, USAF, Retired

“Continuing in the tradition of Without Warning: The Saga of Gettysburg, Terry Pierce has produced another fine historical novel in Thundering Courage.  Here he continues the “you are there” style of writing, bringing the reader into a portion of the battle involving George Armstrong Custer and other notables related specifically to the cavalry actions at the Battle of Gettysburg.  While we cannot know all the dialogue that took place, Pierce comes as close to our imagined dialogue as possible based on meticulous research of the cavalry actions, making for an exciting read.  If you enjoy historical novels, especially those written based on solid research this book is for you!”

– Gettysburg Licensed Battlefield Guide Chris Army