Amazing to see!
I went to the second half of the one in my small Pennsylvania town, and by the count the person on the PA read off, it was about 10% of the town.
People driving by seemed very supportive as well. It was raining really hard the first hour, but when I got there, there was almost no parking left.
I'd never been to a protest before, and it was a different environment than I expected. It had a much more positive vibe, people seemed enthusiastic to be there, even in bad weather. It was great to see so many people there in what feels like a solidly conservative majority area.
I really had a good time, even though I was there by myself and I'm not especially social. A Vietnam vet had me take a photo of him there with his son, so I got to participate in something. It did me good to be around like minded people in a time when I feel alone in worrying about how things are going.
If you're on the fence about going, I say go for it! It was very positive and peaceful for an event about voicing discontent. The feeling of unity was more the focus than what we were there to stand against. Nobody looked angry.
We had a few cop cars there (it's across from the police station anyway) but there were enough people there I didn't actually see any of them, and I changed spots a few times to go around and see everyone's signs and outfits.