The crowd size numbers are beginning to come in:
https://open.substack.com/pub/politicususanews/p/massive-crowd-numbers-are-beginning?utm_source=share&utm_medium=android&r=3aksqTwenty million people protested for Earth Day in 1970 in the United States. The only other protests to come close to Earth Day 1970 were the George Floyd protests. It is possible that No Kings (October) could end up being the second-largest single-day protest in US history.
A better estimate likely won’t be available until Sunday, but the low-end estimate for today currently is that 6 million people will end up attending these protests. The high-end number will be around 10 million.
Either of those numbers would make the fall No Kings protest the second-largest single-day political protest in US history.
= new reply since forum marked as read
.....I doubt that the Earth Day protestors had to be concerned that their own government might arrest them for exercising their freedom of speech.
Or that the supporters of the president might harm them.
Or that the Speaker of the House and Cabinet members might stir up hatred (& potential violence) against them by labeling the Earth Day protestors as domestic terrorists, as we have experienced in this era.
I, too, would love the No Kings numbers to be even bigger, but I think there were some people who stayed home for fear for their personal safety. I think we should feel really good about the turnout, though!
(This is Mrs. Hatrack, hijacking Hatrack's account. Looks like some others made the same point while I was typing this.) 
I am unable to stand for a long period due to physical issues. There must be lots of people like me who are afraid and disgusted and who want to be out there but cannot for one reason or another. 
...report the number of checks he wrote on Saturday? 
Rs totally misrepresenting these protests as paid events and protesters as hating America are making a huge mistake. Nothing from any of the protests suggests the alternate reality they are trying to push--undermining their credibility even more if it is possible.
It is also not fair to compare the Earth Day event in 1970 for several reasons: For one it was--and still is--an outlier event. The largest protest in America before that day is considered to be the 1963 March on Washington for Jobs and Freedom which drew an estimated 500,000 people. And for another it was preceded by the clear impacts of 150 years of industrial development that had finally begun to show up in the daily lives of the average American which encouraged all kinds of groups to unite in common cause. And for another--as has been pointed out here--there was no perception that demonstrating in support of the environment would cause an immediate backlash by government officials--it would take decades for corporate interests to have their revenge through lobbying.
"No Kings" yesterday was an incredible display of solidarity against this regime after only a few months of giving us its worst. And we can take heart in the fact that these events are happening everywhere: in big blue cities and in little red towns! Like it or not, everyone sees what they are doing and will eventually be forced to speak out if they want to keep the way of life America has cobbled together since its inception.