At a time where Budweiser has renamed its beer "America" and bars are constantly filled with patrons chanting "U-S-A!" in support of the athletes competing at Copa America and soon the Rio Summer Olympics, it's hard to imagine that there wasn't a time that the United States didn't celebrate its stars and stripes. However, on the 100th celebration of Flag Day, the holiday is passing by almost entirely unrecognized once again. While some might expect Flag Day started close to the inception of the flag of the United States, as Adam Goodheart, the author 1861: The Civil War Awakening explains, the holiday was first suggested in a Hartford Evening Press editorial by Charles Dudley Warner in 1861.

“It was a moment when the American flag really had the biggest transformation in its history,” he says. “It went from something that was a patriotic symbol and a marker of federal territory, buildings and ships and military use, to being something that was really widely used as a beloved banner for ordinary Americans as well.”

And, as Goodheart points out, there was a commercial element too: during the Civil War, flag manufacturers were making a fortune on flags, and it’s no coincidence that the holiday was proposed in New England, the center of the textile industry. There, for the first time, various dyeing and printing techniques made it easier to mass-produce flags of all sizes. Before that period, flags were made by stitching together fields of solid fabric. Each star had to individually cut out and sewn on. By the Civil War era, however, it was possible to print the colors onto one piece of fabric. “It was really something very new,” Goodheart says, “so the holiday was driven by was commercialization, technology, politics, patriotism—all this stuff coming together and crystallizing in one historical moment.”

Yet, it wasn't until 1916 that the holiday was officially recognized by Congress. Head over to Time to read more.