Stamp Dealers In Washington D.c. Area

Hello,

This is kind of a weird request.

I will be visiting a friend in Washington DC for a week this coming August. I did a google search and a whole bunch of stamp dealers came up for stamp dealers in the DC area. Some of the dealers don't even appear to sell stamps because they only advertise coins on their website while others only have political memorabilia on their website. Needless to say I find the information online very inaccurate and misleading.

Since I will be on vacation visiting a friend and my trip is limited to just one week, I don't want to drag my friend to multiple stamp shops so ideally if you know the DC area can you please give me your opinion on what the best stamp shop in the DC area is.

Thanks.

--Anthony.