Turns out it was an organized protest, we just hadn't heard. The crowd grew and grew. People showed up with free water to hand out.
I got a little bit of video of Apostle Norma Gray, who spoke for the NAACP. And per the Rock Hill Herald:
Rev. C.T. Kirk of Sanctuary of Life Outreach Center in Rock Hill, another main protest organizer, said to the crowd before the march that Rock Hill cannot — and will not — be Minneapolis.In all, over 1,000 residents peacefully gathered to show solidarity. We walked to the police department, three people deep on the sidewalks (many people wore masks). Some had signs, some had "I can't breathe" t-shirts, and "Black Lives Matter." We were proud to walk with them, it was a proud moment to be a part of this community. I'm so glad we were there.
Because, protests like this are one of the reasons we returned to the US. Sometimes just being there can help drive change.