The last protest in America against Trump was the "No Kings" protest. It had over five million people in attendance across 2,100+ locations.
Another one is planned for October 18th. Conservatives are attempting to alter the narrative of this by creating a momorial day for Charlie Kirk on the 14th, but it's also the birthday of George Floyd.
I am guessing this protest will be the target of violence planned by the Trump administration. Still going to attend, though.