Trying to start the day without your morning coffee can feel like going to war. So imagine how important that caffeine fix would be if you were literally going to battle. NPR’s blog The Salt recently sifted through the surprisingly interwoven history of American wars and coffee, specifically focusing on three major conflicts: the Civil War, the Vietnam War, and Afghanistan. Hearing how modern day Marines often bond over a cup of joe probably isn’t a huge eye-opener—being that the average American has three cups of coffee a day even when their jobs aren’t as intense as policing the frontlines of an ongoing conflict—but discovering the extent to which coffee was involved in the Civil War might intrigue those in the U.S. who have become accustomed to the simplicity of firing off their daily caffeine fix one coffee pod at a time.

“Reading through the diaries of Civil War soldiers, nurses, and people on the home front, I went looking for big stories about war and freedom and slavery, secession and union. And all they kept talking about was the coffee they had for breakfast or the coffee they wanted to have for breakfast,” said Jon Grinspan, a curator at the Smithsonian’s National Museum of American History, told NPR. “They wrote the word 'coffee' more than they wrote the word 'mother' or 'war' or 'cannon,' 'slavery,' or 'Lincoln,' even.” It’s actually a comforting reminder that our conversations were inane long before social media.

Not only did coffee fuel the Union Army, with soldiers being issued “roughly 36 pounds of coffee each year,” according to a New York Times article from Grinspan fittingly titled, “How Coffee Fueled the Civil War,” but after the Union’s naval blockade restricted coffee imports from reaching the Confederacy, a lack of caffeine became the bane of the South’s existence. One Brit suggested that this lack of coffee “afflicts the Confederates even more than the loss of spirits”—a dire situation indeed!

Though Grinspan doesn’t believe coffee was the deciding factor in the Civil War, he does point towards how emblematic the North’s use of coffee was. “The way Union soldiers gulped the stuff at every meal pointed ahead toward the world the war made, a civilization that lives on today in every office breakroom,” he wrote in 2014.

Though consuming coffee in itself was not a novelty by the time of the Vietnam War, the social significance of drinking coffee remained. NPR specifically cites the importance of the G.I. coffeehouses as meeting grounds for the anti-war movement—creating “a place where soldiers could gather and talk openly about their worries and frustrations, without the military brass around,” according to Fred Gardner, an Army Reservist who opened the first of these G.I. coffeehouses in Columbia, South Carolina, in 1967. This coffee-centric scene even caught the attention of Hollywood. “Jane Fonda and Donald Sutherland created an anti-war cabaret called the FTA show,” said Gardner. “She was very much involved with supporting soldiers who were opposed to the war in particular. The coffee houses were the starting point for that movement.”

In even more modern times, soldiers in Afghanistan also understood the importance of bonding over coffee. “That's how pretty much every new relationship in the Marines is formed,” Harrison Suarez said in an interview with NPR. When he returned from Afghanistan, Suarez and fellow Marine Michael Haft even started their own coffee company, Compass Coffee, in Washington, D.C. They now fulfill the generations-long tradition of getting soldiers the coffee they’ve needed to fight for their country since at least the 1800. “We've sent coffee to Marines on aircraft carriers, to Afghanistan,” Haft told NPR. “Basically any time any soldier requested some crazy coffee delivery, we've done our best to accommodate getting it out to them.” Sounds like the Confederacy could have used Compass Coffee back in the 1860s.

In the end, considering the relationship between war and coffee isn’t just interesting, it’s also humanizing. In the craziness of war, we can sometimes overlook that soldiers are people living day-to-day just as we are. Coffee is one of those things almost anyone can bond over, soldier or not. And it reminds us all who the real enemy is: tea drinkers. How do they do it?