Sorry to post so much later, but I did not see your question answered previously. Pho is Vietnamese beef noodle soup. Delicious! And there are plenty of places that serve it in the DC area. My personal favorite is
Pho 75, which is a hole in the wall as far as decor, but man oh MAN that soup is good.
On a side note, I have always heard that the name Pho 75 does indeed come from 1975 -- in my experience the DC-area Vietnamese community is patriotic and very pro-American, but they also remember their heritage and defend it passionately. As they should!