This is the Poplar Spring annual vegan Thanksgiving. Its the Saturday before Thanksgiving.
I've been to this event several times and there is always a huge amount of vegan food and hundreds of people in attendance. Here's their description on the website:
Come celebrate Thanksgiving WITH the turkeys - join our friendly turkeys and all their friends in celebrating a cruelty-free Thanksgiving potluck. Please bring a vegan (no meat, dairy, or eggs) dinner or dessert item to serve 8. $10.00 suggested donation to benefit the animals. No charge for children under 16.
It's great to have a Thanksgiving dinner that you can eat, instead of fasting because there's nothing vegan served (like many Thanksgiving dinners unfortunately).
This is not metro accessible but please post if you need a ride from a metro stop and we can coordinate rides.