Then, after a day of unprecedented bloodshed, McClellan balked at pursuing Confederate Gen. Robert E. Lee's crippled forces as they retreated across the Potomac River, missing an opportunity for a decisive victory.
"McClellan was timid in battle," said George Wunderlich, who conducts leadership training on western Maryland's Antietam National Battlefield. "Because he held back, because his communication was not clear, because he was not able to step up and take command when he should have, we have 5,000 more causalities."
Wunderlich is executive director of the Frederick-based National Museum of Civil War Medicine and its new leadership branch, The Letterman Institute. It's named for a Union army surgeon whose innovations such as an ambulance system for evacuating wounded soldiers at Antietam are still saving lives.
Wunderlich is not alone in using hallowed ground to teach management lessons. From Pearl Harbor to Little Big Horn, trainers are leading executives and managers across landscapes scarred by armed conflicts.
"You can stand on the field where the decisions were made and then see the immediate and dramatic consequences of that decision - and then make the leap into the current world," said Sue Boardman, leadership program coordinator with the 3-year-old Gettysburg Foundation in Gettysburg, Pa.
With the nation at war and management-as-warfare a popular book theme, the approaching Civil War sesquicentennial is a ripe time for teaching leadership in places where teamwork, communication and goal-setting could mean life or death.
"If you can learn to lead here, you can learn to lead anywhere," Wunderlich told managers from banking, consulting, church and governmental agencies during a tour of Antietam. The group spent a morning traversing rolling farmland in a white van while absorbing battlefield lessons.
Retired Army Lt. Gen. Dan Christman, senior counselor to the U.S. Chamber of Commerce, has taken chamber leaders on two tours of Gettysburg.
He said Union Col. Joshua Chamberlain's defense of Little Round Top, a rocky hillside, on July 2, 1863, is a timeless lesson in communicating clearly and building loyalty.
"Every corporation finds a moment in its history when you need a leader to take initiative at a crucial moment," Christman said.
Jason Howard of Chattanooga, Tenn., sent hundreds of managers on tours of Chickamauga and Chattanooga National Military Park as director of organizational development at Blue Cross Blue Shield Tennessee.
Now a self-employed consultant, Howard said the "Battle-Ready Team" program run by Trident Group LLC convinced him that "all business strategy comes from military strategy."
His favorite battlefield figure is Union Gen. George H. Thomas, nicknamed "the Rock of Chickamauga." Thomas' heavily outnumbered troops staunchly resisted a Confederate force in September 1863.
The takeaway message: Amid the mayhem and hysteria, "he was able to control his people," Howard said. "More important, he was able to control himself."
Steve McCloud launched the Trident Group in 2005. He cites Confederate Gen. Braxton Bragg as a poor leader, despite his victory at Chickamauga, because he tended to blame others when things went wrong.
"'I did my job. I sent the e-mail' - that's the lesson of Braxton's army."
McCloud's 4-year-old company also runs seminars, priced at $400 to $1,000 per person per day, at Gettysburg National Military Park and two South Carolina battlefields.
The Army has been sending officers on "staff rides" to Civil War sites since 1890. Private tours date to at least 1915. But executive historical leadership tours are a more recent invention.
One of the oldest operators is Tigrett Corp., founded in 1984 in Gettysburg by Everett and Antigoni Ladd. The company's 11 workshops include "Lessons from Pearl Harbor," held in Hawaii, and "Lessons from Little Bighorn," in Billings, Mont. A three-day program for 12 to 30 people runs about $15,000, excluding hotel costs.
Mrs. Ladd said the Little Bighorn seminar celebrates Sitting Bull's skill in building a coalition of tribes to oppose Lt. Col. George A. Custer in 1876.
She said the seminar is perfect for organizations undergoing big change: "The magic is in how he persuades multiple levels of people to do something that is almost counter to their cultures."
The Ladds happened to launch their business as military strategists began invading the business book shelves. Barrie James' "Business Wargames," was published in 1984, followed two years later by "Marketing Warfare," by Al Ries and Jack Trout. Wess Roberts' "Leadership Secrets of Attila the Hun" came out in 1987.
Recent additions to the genre include a 2005 edition of "Marketing Warfare" and "In Extremis Leadership: Leading as if Your Life Depended on It," a 2007 book by West Point professor Col. Thomas Kolditz.
Lorraine Shanley, principal with Publishing Trends newsletter owner Market Partners International, couldn't confirm that the genre is hitting another peak but said such books are "the backbone" to a business segment that is thriving in the slow economy.