Americans use "D.C." (short for "District of Columbia") to distinguish the Federal District of Washington from the state of Washington in the northwest of the country. (I think it was a poor decision to give the state the same name as the district, but we're stuck with it now.) In many contexts, it's clear which one is meant, so the "D.C." can be omitted, but there are other cases where it is used. I note that a number of the translations (like this one) omit the "D.C.", but it would be better to include it if there's an accepted way to do it in Portuguese.

Hi, Alan!

Thank you very much for your comment, it was very interesting!

Well, I believe that the situation in Brazil the situation is as follows (at least from my point of view): hardly often do we need to make such a distinction. As we don't talk about the state of Washington very frequently, this confusion hardly ever happens here. What is "famous" and better known to us is the capital, generally speaking.

Therefore, the use of "DC" or "D.C." after Washington is often left out among English-speaking Brazilians. Some people use it, some people don't.

Anyway, considering your comment and taking into account that some Brazilians do use "DC" after Washington (the capital), I'm following your suggestion and changing the sentence.

Thanks, have a great weekend!

All the best,

Matheus