What if the Union Army had machine guns at the Battle of Gettysburg? What if Robert E. Lee had observation balloons to spy on his opponents? These are the sorts of questions that tempt alternative history buffs. The popularity of speculative novels and movies demonstrates that humans can’t resist the chance to explore what might have been.

But some are putting alt history to a more practical purpose: teaching U.S. military officers to deal with the impact of new technologies. New weapons, such as drones and hypersonic missiles, have revolutionized war and sent armies scrambling to devise new tactics.

So why not use the past to spur thinking about the future? That’s why the RAND Corporation think tank devised a Gettysburg wargame futures program for the U.S. Army, which deals with questions such as what equipment and doctrine the Army will need in coming years.

“The whole idea is to create an historical laboratory,” Gian Gentile, a retired Army colonel and historian who is now deputy director of RAND’s Arroyo Center, told Popular Mechanics. “Using counterfactuals that will allow the players to learn from them, and apply them to their present and future thinking.”

The RAND game took an historical event, but made a few counterfactual changes. This Battle of Gettysburg would feature the historical armies, but they would be armed with advanced equipment—not with lasers or guided missiles, but technology that was actually available in 1863, yet which the Union and Confederacy failed to take advantage of.

The Real Gettysburg

Gettysburg is one of the most closely studied battles in history. Broadly speaking, it was a sort of accidental battle. Robert E. Lee led his Army of Northern Virginia on an invasion of the North, whose success might induce the Union to agree to peace. Advancing into Pennsylvania, Lee’s troops stumbled into George Meade’s Army of the Potomac at the town of Gettysburg. What began as a surprise encounter between Union cavalry, and hungry Confederate infantry in search of supplies, became a massive three-day battle as the South sought to dislodge Union forces from positions such as Cemetery Ridge and Little Round Top. The battle ultimately cost 50,000 casualties—and marked the beginning of the end for the Confederacy.

the battle of gettysburg lithograph

Heritage Images//Getty Images

The Battle of Gettysburg, color lithograph, published 1863.

Both armies suffered from 19th century problems: ponderous command and control conducted through couriers who had to physically deliver messages to commanders on the battlefield (telegraphs existed but were limited to fixed sites), and troops burdened with cumbersome muzzle-loaded rifles and cannon with a slow rate of fire.

However, better technologies did exist: Gatling guns (an early machine gun), observation balloons, rapid-fire breech-loading rifles, and field telegraphs portable enough to accompany combat units.

For various reasons, the North and South failed to exploit these technologies. For example, breech-loading Sharps repeating rifles could fire 10 rounds per minute, or more than double the rate of a muzzle-loading rifle. Yet while some Union cavalry used repeating rifles with devastating effect at Gettysburg, most troops stuck with the muzzle-loaders. “Federal supply and ordnance officers resisted buying the Sharps in large numbers, judging that the rifle’s high rate of fire would potentially lead soldiers to waste ammunition, thereby stressing a supply system that already struggled to keep up with demand,” noted the RAND report.


RAND actually conducted two sets of games. The first was played in 2018, and began with the battle in progress on Day 2 of the struggle. The 2021 sessions began on Day 1 as the armies advanced to contact, and thus allowed the players to employ different maneuvers than Lee and Meade did. It was also a “double-blind” game controlled by umpires, where the opposing teams didn’t see each other’s forces on the map unless the referees decided they had been spotted by reconnaissance.

Though the simulation featured technology that was the ancestor of modern equipment, RAND avoided the temptation to turn Gettysburg into the Battle of the Bulge or Desert Storm. For example, there was just one field telegraph system at each of the opposing army headquarters, with wires that extended eight miles to each corps’ headquarters. There were also a few telegraph-equipped observation balloons that could watch enemy movements up to 10 miles away.

Reflecting pre-radio command structures, the army commanders (the players representing Lee and Meade) issued orders to their subordinates each turn. But several game turns might elapse before the recipient was considered to have received the message by courier. However, telegraphed orders were deemed to have been received immediately.

gettysburg wargame map

RAND Corporation

The wargame map.

As for combat, resolved by rolling dice and consulting charts, a repeating rifle had triple the firepower of a rifled musket, and a Gatling gun had 200 times the firepower. However, the Union Army had only eight Gatling guns and two brigades armed with repeating rifles, and the Confederates had just six Gatlings and one brigade with rapid-fire rifles.

As intended by the game’s designers, this newfangled weaponry sparked vigorous debate among the players about how best to employ it. “We had some people who thought that the best way to use the good rifles was to spread them out and stiffen everyone,” recalled Michael Linick, a RAND defense researcher and retired Army colonel who helped umpire the game. “Others massed them into one big hammerhead formation.”

Tactics Over Technology

To some extent, the new weapons and communications systems in the game did change history. “The Confederates used their additional firepower to penetrate the Union line, seizing Cemetery and East Cemetery Hill,” Gentile said. “The Union used their telegraph to improve the command and control over their forces and their balloon to maintain awareness of the locations of the Confederate infantry corps. Thus, they maintained the integrity of their army despite the Confederate tactical success.”

Interestingly, with the armies beginning the game locked in combat, the 2018 session mostly proceeded historically. “The new technologies, without different operational concepts, produced similar results as the actual battle, albeit with some modest improvements,” said Gentile.

But in the 2021 sessions, the biggest change was caused by what Lee and Meade’s successors 150 years later would call ISR—or intelligence, surveillance, and reconnaissance. “There were instances where the [ahistorical] firepower did make a difference,” Sean Barnett, a senior engineer and wargame designer at RAND, told Popular Mechanics. “But it was mostly the ISR that had an impact.”

The Union and Confederate teams both centered their battle plans around the new technologies, but in different ways. “In one game, the Confederates started the game by making information advantage their overall operational goal and built their plan around it,” Gentile said. “They kept one of their balloons hidden so as not to give away their positions and maneuvered out of the observation range of the Union balloons. The Union built their plan around their observation capabilities, so they were fighting for information. They used their cavalry to try to deny situational awareness to the Confederates.”

Command and control in the 19th century was often erratic, with primitive communications, unreliable reconnaissance, and commanders that had a habit of either ignoring or disobeying orders. But the addition of a few field telegraphs created a more modern and efficient command structure—though with a catch. Unlike radios and cell phones, telegraphs in the 1860s were semi-mobile at best. In the simulation, once a headquarters moved, the telegraph was considered to be down for several turns.

“As soon as you start to move, the advantage of the telegraph starts to diminish immensely,” Linick said. “So what is the right moment in the battle to break free of the telegraph and start to maneuver? When do I allow my C2 [command and control] to be degraded?”

Nineteenth-century armies also relied on cavalry for reconnaissance, both to collect information about enemy forces and to screen friendly troops from probes by enemy cavalry. But the presence of telegraph-equipped balloons, which could see much further than a scout on horseback, gave cavalry a new mission.

“The balloons became high-value targets,” Linick said. “Cavalry can’t screen against a balloon. So cavalry now becomes the balloon hunters. To shoot them down, capture them, or make them move.”

Past Battles Predict Future Battles

Historical wargaming, whether around a kitchen table or at a military staff college, is a stimulating way to learn history. It’s more immersive to step into the shoes of historical commanders, rather than simply reading a book or watching a PowerPoint presentation.

In that sense, the RAND Gettysburg game proved valuable for more than training soldiers. It gave some of the vast assortment of backroom people who keep the U.S. military machine running—planners, analysts, budgeters—a taste of battlefield command. “The sort of decisions you have to make in the office are fundamentally different from out in the field,” Karl Mueller, a RAND political scientist, told Popular Mechanics. “For a lot of people whose work ultimately affects the people out in the field, they don’t often get that opportunity to see how the operational commanders do their jobs and what’s important to them.”

battle of gettysburg civil war alternative history wargame

RAND Corporation

Pieces in play on the wargame map.

Gentile believes RAND’s game can be used to explore other historical battles, with an eye toward future lessons. “They can be used to gain insights about the adoption of technologies, the cost-benefits of modernization, and the impacts that different approaches and choices have on the battlefield.”

Linick sees wargaming as a way to understand the spinoff effects of new technology. For example, balloons in the Gettysburg game forced players to deal with issues such as how to provide security for a vulnerable balloon. “Let’s say you are looking at the U.S. Army of 2035, and trying to understand how a proposal for an unmanned combat vehicle may change the way an operation unfolds,” Linick said. “This kind of game gives you a relatable learning experience to think about how introducing new technology has effects. All too often, we get the narrow questions answered when we add a new system, but it takes too much time to understand the second- and third-order effects.”

Ultimately, while this kind of defense wargaming has similarities with alternative history movies and novels, there is a big difference. Writers must have “an outcome that fits their plot,” Linick said. “In our game, I don’t care what the outcome is. I do care how people thought about their decision making, and how those decisions led to the outcome. What they do is narrative. What we do is discovery.”