On April 17, 2009, the Nationals were hosting the Florida Marlins at the recently completed Nationals Park. Fans soon noticed that two of the Nationals players, Ryan Zimmerman and Adam Dunn, were both somehow missing the letter O in their jerseys.
Dunn and Zimmerman wore shirts proclaiming “Natinals” for the first three innings of Washington's 3-2 loss to the Marlins. They eventually changed into correctly-spelled jerseys, but not before the mistake became iconic.
A few days later, the company that made the jersey, Majestic Athletic, took “100% responsibility” for the mistake. But the damage was done. Mostly because the symbolism was far too on point.

Washington Nationals baseball outfielder Adam Dunn. (Photo via AP Photo/Charles Dharapak)
You see, in classic D.C.-style, the Nationals were having a dumpster fire of a season. The mistake felt like the final blow to many fans who were frustrated with the team. In the long run, the typo became a running joke that whenever the Nats did something bad, it was, in fact, the Natinals.
The infamous “Natinals” game is on YouTube if you want to spot the misspelling yourself.