The Answer
The Walgreens logo was introduced first in the 1950s. The Washington Senators stylized W (on which the Nats logo is based) emerged in 1963.
In case you haven’t noticed, the stylized W logo of each of Walgreens and logo of the Washington Nationals are nearly identical. In fact, even National’s fans recently had trouble working out which was which.
Even Walgreens recently had some fun with the with the similarity on Twitter.
When did the Walgreens W appear?
In 1951, Walgreens introduced a precursor to their current logo that shows Walgreens in a cursive script, featuring the now-familiar capital W.
What about the Nationals logo?
There is an argument here to say that the current Nationals logo is no more than about 15 years old. In 2005, the Montreal Expos moved to Washington and the Nationals were born, or perhaps re-born. The team was named after the original Washington Senators baseball team, which had been nicknamed the Nationals. The Senators left Washington in 1971, moving to Minnesota to become the Twins.
As a tribute to the original team, the new Washington Nationals adopted the stylized W logo used by the former Senators. That logo had been in use since 1963.
So, it seems that Walgreens has existed for longer than the Nationals logo. However, with the current success of the Nationals and the exposure they’re getting, I’m not sure they mind too much.
Despite confusion over the two symbols, Walgreens — which used a curly W long before the Senators did — hasn’t sued Major League Baseball for a trademark violation. That’s surprising, considering the company sued grocery chain Wegmans over this exact issue before.