Here’s a card that my mom sent to me from Philadelphia, back in December when we visited Independence Hall and Valley Forge:
Although the soldiers were men, there were many women at the encampment. Around 500 camp followers helped keep soldiers’ morale high and laundered and mended uniforms, among other things. They were even paid for their service.
There’s nothing special about the stamp, but check out the postmark:
The mark comes from the B Free Franklin post office in downtown Philadelphia. It is a few blocks from Independence Hall. This post office was founded by Ben Franklin and is the only US post office to not fly the American flag. Know why? It’s because it was founded even before the USA was a country! It’s been in continuous operation ever since. If you go, you can get all your mail hand cancelled with this special stamp.