This is the U.S. Naval Academy’s idea of spring break: a 70-mile march along the craggy spine of the Blue Ridge Mountains, in a sesquicentennial tribute to Confederate Gen. Thomas J. “Stonewall” Jackson and his torturous Shenandoah Valley Campaign.

Fourteen midshipmen forsook Cancun or Panama City last month for a five-day slog along the Appalachian Trail, eating peanut butter and gorp and drinking water collected from mountain streams. Only nine completed the journey. Injury and exhaustion claimed the rest — a development that only reinforced the week’s lessons about hardship and resolve.

The Valley Campaign of spring 1862 secured Jackson’s legacy as a consummate military leader. Jackson’s “foot cavalry” marched 646 miles in 48 days and won a string of improbable victories against larger but separated Union forces, including memorable contests at Front Royal (May 23) and Port Republic (June 9). The Federals were prevented from reinforcing a drive on Richmond, and Jackson eventually slipped away from his befuddled enemies in the valley and joined the forces that drove the Union army away from the Confederate capital, fueling Southern hopes of winning the Civil War.

Retracing some of Stonewall’s steps heralds a new academic approach at the Annapolis academy, one of five federal service academies that train future officers. Midshipmen are among the few college students required to study leadership — and to learn the skills well enough to lead sailors or Marines into battle.

“We can’t take these kids over spring break to Afghanistan, nor would we necessarily want to,” said Joe Thomas, a professor of leadership education at the academy who led the Valley Campaign expedition from March 11 to 16. “But we can take them to somewhere in their back yard that has really valid, timeless lessons for people who are going to go to Afghanistan in a few years.”

Past generations studied leadership mostly in the classroom. In recent years, though, the emphasis of leadership training in Annapolis has shifted to what academy instructors call “epic” experience — lessons learned in real life. It’s part of a broader educational movement toward experiential learning. Groups of midshipmen go sailing in Maine, kayaking on the Chesapeake or hiking in Alaska, learning to lead in places where decisions can have life-

altering consequences. Other military schools, including the Air Force Academy in Colorado Springs and Virginia Military Institute, also teach leadership in real-world settings.

“Optimism is a force multiplier. Keep that in mind,” Thomas said, addressing a circle of weary midshipmen. It was dusk on Day Three of the hike, and Thomas was doing what he could to buoy spirits after 55 miles on foot.

Jackson’s troops crisscrossed the valley from February to June of 1862, marching from Winchester to Port Republic, up into West Virginia and across the mountains to Charlottesville.

(Civil War completists will note that Jackson’s men passed through Swift Run Gap, where Thomas and his midshipmen camped, around April 17. Confederate records show the “foot cavalry” slept “exposed in open bivouacs to the snow, rain and sleet,” a far cry from the balmy sunshine that greeted the midshipmen in mid-March 150 years later.)

Thomas’s midshipmen, 13 men and one woman, took a path that was shorter but harder, hiking south from Front Royal to Waynesboro along parts of the 2,180-mile Appalachian Trail and descending into the valley in a pair of white cargo vans to visit battle sites. The vans allowed them to hop around on the trail.

Some of the students knew one another from Thomas’s class “Military Ethics: The Code of the Warrior,” a semester-long meditation on the nature of military leadership and the value system that distinguishes warrior from murderer.

But this was an entirely different experience: an endless ribbon of rocky trail, every step pounding feet, twisting ankles and knees.

“People see ‘Appalachian Trail’ and think it’s going to be a trail,” said Jackson Thornton, 21, a senior from Liberty, Tex. “It’s not like a sidewalk. By the end of it, we hated going down more than we hated going up. It was like falling on your feet.”

Day One took the group roughly 17 miles, from Front Royal to a camp north of Sperryville. Day Two was 22 miles to a camp west of Old Rag. Day Three was 16 miles to Swift Run Gap. Day Four was a side trip to Old Rag, 11 miles up and down. Day Five took the midshipmen six final miles to McCormick Gap.

The midshipmen took to the trail head at the peak of youth and fitness. But the rocky terrain “turned their feet into hamburger meat,” said Thornton, a lifelong hiker who completed the journey relatively unscathed.

He said the expedition taught him that “when the going gets tough, you need to be able to step out in front and say, ‘Follow me.’ ” Surrounded by suffering, Thornton did his part to lift spirits by quoting lines from the movie “Dumb and Dumber” and acting “like I was out on a stroll with friends.”

Thornton walked in “homage to my ancestors” — specifically,

a great-great-great-grandfather, Willis Thornton, who fought with the 2nd Louisiana Infantry until he caught a Minie ball in the knee at the Second Battle of Bull Run in August 1862.

“I was trying to play it as period as I could,” Thornton said. He wore a Confederate cap and packed lightly: a few dehydrated meals and a couple of PowerBars.

“Their rations were five ounces of bacon and two ounces of cornmeal a day, and that can fit in one hand. It’s not much,” he said. “But those guys were smaller than we are.”

Unlike many of Jackson’s troops, these midshipmen had shoes. But for some, the footwear proved a hindrance. Several midshipmen arrived with stiff new hiking boots that hadn’t been broken in. By the second day, their ankles were bruised purple. The outing became an exercise in pain management.

“You put it away, don’t think about it,” said Kieran Simonson, 21, a sophomore from Zionsville, Ind. “As soon as you start thinking about pain, it amplifies itself. Start whistling a song. Talk to somebody. Listen to the bird calls. Do anything to avoid it. We kind of have a saying here. It’s called, ‘Suffer silently.’ ”

The journey was filled with what Thomas called “teachable moments.” On the first day, one of two hiking groups walked past a crucial water source and went thirsty. On the second day, the lone female hiker suffered such pain from her boots that she finally removed them and walked several miles in socks. One group overshot the camp and didn’t get in until near midnight.

“They got lost,” said Michael Gonzales, a sophomore from Sacramento, sitting at a picnic table near dusk on Day Three.

“We didn’t get lost,” Simonson said. “We went straight past where we were supposed to.”

“Which is lost,” Gonzales said.

Vans shuttled the midshipmen between battlefields and hikes — but not to motel beds or hot meals. A rare exception was dinner on Day Three: a case of hot food brought from Famous Dave’s BBQ.

“We’ll go oldest in the rear, youngest in the front,” Thomas said, supervising the food line. “Everybody knows officers eat last, right?”

Hiking boots were removed, blisters compared and ibuprofen distributed. Some midshipmen could barely walk. As the group hobbled toward the camp site, one midshipman observed, “This is like march of the zombies.”

Around the circle at dusk, the midshipmen talked about Elisha Hunt Rhodes, the Union officer who once marched his regiment 34 miles without stop. And about the toil that still awaited all of them. “The things I’m concerned about with a lot of you, I’m looking at a lot of swelling knees and swelling ankles,” Thomas said.

“Pat yourselves on the back, all right? We’ve had some pretty aggressive hiking.”