MSNBC's Lawrence O'Donnell does a short history of inauguration protests to explain why the Women's March was so significant. "The American news media was not exactly filled with predictions of the protests' future successes."

In North Dakota, the proposed law would open big loopholes for drivers who strike protesting pedestrians. Other states have considered "economic terrorism" charges and other anti-picketing measures, all part of a targeted response to Black Lives Matter and anti-pipeline activists successfully blocking roadways.

There's a good reason Dr. King's last book was called Where Do We Go From Here? As every good organizer knows, follow-up is one of the hardest parts of activism. And after the success of Saturday's march, there are lots of questions about where that momentum goes next.

While some see parallels with Russia's anti-Putin protests that went nowhere, organizations are already looking to skill up enthusiastic volunteers. "Organizations need to be ready to receive the protesters when they’re ready to take the next step." 

21: Renditions of "Happy Birthday" sung by protesters to a policewoman serving on her special day.

6: Age of Sofie Cruz, immigration activist who melted hearts and called for all to "fight with love, faith, and courage."

3: Times larger the crowd was on Saturday than Friday in Washington, according to crowd experts.

430,000: More Metro trips taken on Saturday than Friday in Washington. 

-20: Degrees Fahrenheit in Fairbanks, where 2,000 marched.

5: Million people estimated to participate worldwide.

32: Trump's approval rating at the time of the march.

An examination of marches in American history reveals a mixed record of success, often delayed. It took 20 years to see any results from the massive 1987 gay rights march, for example. 

Here's a neat map of marches, protests, and rallies that have taken place in Washington over the past century, that gives some context on size. The March on Washington was smaller than Saturday's march, while the Million Man March was bigger.