But while the Peck and Snyder No. 1 may have kicked off the baseball cap revolution, it looks more like a beret or a deflated soufflé sitting atop someone's head compared to today's lids. Those same Brooklyn Excelsiors then brought us much closer to today's baseball cap, with what is now known as the "Brooklyn-style cap." The brim went longer and it had a deeper, button-topped crown.

"In the 1850s, especially by the late 1850s when you have a decent number of images, you're definitely seeing people wearing what you and I would think of as a baseball cap, which is a crown with a bill that comes out just one direction instead of all the way around," Shieber said. "This is not a particularly groundbreaking object. Really, something like that had been worn in horse racing by jockeys for many years. We call it a baseball cap because we're Americans and it's just been associated with baseball for a long time. But it's not like it was invented for baseball. The cap had been around a long time."

While there were other styles -- including the famed pillbox, which practically screams the 1800s -- it was this "Brooklyn" style that took off. By the end of the century, one cap had clearly won out, even though there were plenty of others around.

Perhaps shockingly, while we think of the pillbox as the standard historical baseball cap -- just go to any vintage baseball game in your area and you'll see that's certainly the case -- it actually had a very short period on baseball players' heads.

"It wasn't until the late 1880s, really, where the pillbox becomes popular," Shieber said. "I mean, we're dabbling in it before that, but its height of popularity was in the late 1880s. But it doesn't really last that long, surprisingly. From a modern standpoint, you say 'old timey baseball' and everyone thinks of a certain kind of mustache or a beard."

(Oddly enough, the Philadelphia Athletics wore pillbox caps during their height of success in the early 1900s. This helped re-popularize the cap, but could also be considered a type of uniform throwback. Oddly enough, teams were wearing nostalgic baseball uniforms in the 1880s and '90s, already harkening back to an earlier time.)

While these early models had the look and feel of a modern ballcap, they were still lacking that all-important logo on the front. That would come in 1894 when the Boston Baseball Club -- now the Atlanta Braves -- became the first team to wear letterforms when they donned a monogram-style look on their caps. Three more teams would join in on the fun the next year.

It would take another seven years before a mascot first appeared on a Major League hat, when the Detroit Tigers proudly displayed a red tiger on a dark ballcap in 1901. The tiger -- which looks a little like a child's drawing of the animal -- would be replaced by the letter "D" in 1903, with the now-iconic Olde English-style letterform showing up a year later.

While the Tigers are often credited as the first to pull off the mascot lid, that's maybe not entirely accurate.