Americans everywhere are clinking coffee mugs to celebrate National Coffee Day, but few know that the histories of the U.S. military and the flavorful bean are closely intertwined.

Coffee has been consumed by humans since the 14th century, and American military members have been enjoying a morning cuppa since coffee was added to the standard military ration in 1832. Capt. Robert K. Beecham, a member of the Union army, wrote that soldiers depended on coffee to keep moving forward during arduous marches during the Civil War.

“The power of the soldiers to endure the fatigue of the march and keep their places in the ranks was greatly enhanced by an opportunity to brew a cup of coffee by the wayside,” Beecham said.

The drink gradually rose in popularity, but sales didn’t skyrocket until World War I. During the war, more than two million American soldiers would have three cups of coffee a day while fighting overseas. By World War II, the Army Quartermaster Corps estimated that each military member drank 32.5 pounds of coffee a year.

Naturally, soldiers who consumed coffee during war brought their habits home. The rise of advertising and international trade with coffee-producing countries made coffee even easier to feed the military’s caffeinated habit and spread it to American households.

Coffee still plays an important role in the military community today. Military veterans First Lt. Harrison Suarez and First Lt. Michael Haft wrote in their e-book “Perfect Coffee at Home” that they relied on coffee to remain alert and battle-ready throughout their military careers.

Whether you plan to brew your own roasted coffee or hit up the nearest Starbucks, remember how the coffee craze of the American military helped bring the bean to your breakfast.