End of day update: Much of the day was peaceful, notwithstanding the clashes toward the end of the day. The final estimates: somewhere between 30,000 and 40,000 counter protestors showed up to stand up for equality and to oppose white supremacists. Their numbers dwarfed the 100 or so who attended the "free speech rally," which wound up ending early.
5:09 p.m.: The fighting has moved to Downtown Crossing. Our photographer, Meredith Nierman, said there are pockets of "total chaos." People are fighting with police, who are being hit. Bottles are being thrown at officers. After an officer chased down a protestor and took him down.
4:40 p.m.: During a press conference, Boston Police Commissioner Bill Evans said 27 arrests have been made so far and there was no significant property damage to the city. He estimates there were about 40,000 people on Boston Common today.
4:35 p.m.: Craig LeMoult reports that the police are backing off of the protestors on Tremont. They appear to be letting the protest run it's course. The street is currently impassable.
4:14 p.m.: Tensions are still running high on Tremont Street as protesters continue to chant as police try to keep the street clear. They are chanting of "Black Lives Matter!" and "F Donald Trump!" Earlier, reporter Craig LeMoult saw a convoy of bike cops applauded and thanked. Now people are yelling, "Cops and klan go hand in hand."
3:38 p.m.: Protesters were blocking police on Tremont, chanting "Whose streets? Our streets!" Two of our reporters heard some people scream "Nazi escorts" at police.
2:55 p.m.: Though most, if not all, of those attending the "free speech rally" have left Boston Common, there is now a Black Lives Matter demonstration happening at the corner of Charles and Beacon Streets.
2:18 p.m.: A handful of counter protestors spoke with Boston Public Radio today. They described an uplifting community of people who were supportive of each other. One person who came from Oxford, Mass., said he came to restore his faith in humanity and expressed gratitude that Massachusetts gave him the opportunity to turn something that was trying to be negative into something positive. People were handing out food and water bottles. People were hugging and flowers were being thrown. Another person from Worcester said, "I couldn't sit down and be quiet anymore. I have lots of mixed feelings but I don't think this is the place for hate."
1:45 p.m.: Our reporters on the ground are reporting that it seems like people came to fight, but the Boston police has done a relatively good job of keeping them apart. That said, there were thousands more also yelling "no violence" at points. As "free speech rally" participants were leaving, counter protesters were booing and yelling that they should be made to walk. It's unclear how many counter protesters there are. The AP is reporting 15,000 showed up today, but the Boston Police Department can't confirm that number.
1:07 p.m.: The crowd was bracing itself for pepper spray. They were putting on helmets and goggles, while police gently push back counter protesters. The police are forming a human barrier between the two factions while the rally sympathizers get on police wagons.
12:58 p.m.: One of our reporters on Boston Common, Bianca Vasquez-Toness, is reporting that the "free speech" rally is breaking up and police are trying to find them a safe way out. Thousands of counter protesters were waiting for them and taunting them. Police have been pulling rally sympathizers from the crowd and escorting them to an area behind the gate. The police, who are in riot gear, are worried about letting the groups meet.
12:51 p.m.: Tammy Lee is a scheduled speaker who was having trouble getting into the rally area. She told WGBH News' Bianca Vasquez Toness she "feels sorry" for the counter demonstrators, who don’t get it, adding that they paint everyone with a broad brush of hate.
“There can be neutral parties that are fighting for all rights. And if you can't understand that and you categorize us as a hate group, then I feel sorry for you.But I will still protect your rights and freedoms without prejudice," she said.
She also says that given what she sees out there, it took courage for the "free speech" ralliers to show up.
“We have already experienced a lot of anger, a lot of aggression. We're being called all kinds of names," she said. "They don't even know who we are, it's just instantly, ‘you must be Neo-Nazi, you must be this.’ And that's the problem.”
12:45 p.m.: "Free speech rally" participants begin to leave the Parkman Bandstand.
12:34 p.m.: The crowd at the Parkman Bandstand is much smaller compared to the number of counter protesters.
Crowd goes after guy in Make America Great Again hat. @wgbhnews pic.twitter.com/nSTfA6L27Q— Craig LeMoult (@clemoult) August 19, 2017
11:54 a.m.: Tensions grow as the crowd surrounds one man wearing a "Make America Great Again" hat.
11:28 a.m.: The march from the Reggie Lewis Center in Roxbury to Boston Common begins.
10:53 a.m.: A large crowd is rallying in front of the Massachusetts State House.
10:50 a.m.: Things begin to heat up on the Common with counter protesters yelling "Make racists afraid again" and "shame, shame."
10:30 a.m.: Thousands begin assembling at the Reggie Lewis Center in Roxbury for a march to the Boston Common to oppose the rally.
9:00 a.m.: Security is posted, and large trucks and fences are placed along the Boston Common. People begin to trickle in.
8:30 a.m.: Some — but not all — businesses around the Common are closed today amid concerns about getting involved in what could be a tumultuous protest.
Over the past week, Boston has been bracing for a chaotic — and potentially violent — set of protests. After the events in Charlottesville, Virginia, where one woman was killed and several others were injured allegedly by a white supremacist, many fear the event will attract more white supremacists and Neo-Nazis.
Organizers of the so-called free-speech rally, which is set to start today at noon on Boston Common, have tried to distance themselves from the hate groups that were carrying torches and chanting racial and anti-semitic slurs in Charlottesville. They say they are hoping to bring people together to discuss the importance of the First Amendment and freedom of expression in an overly politically correct environment. But a growing counter protest — which includes disparate groups like Black Lives Matter and "antifa," a far-left anti-fascist group — sees the "free-speech rally" as a cover for darker, racist impulses.
Though this rally was planned before the tumult of Charlottesville, the deaths of Heather Heyer and two police officers loom over the event. Several speakers have dropped out, citing security concerns. City officials have been preparing this week to keep the 300 or so "free speech" participants that are anticipated cordoned off from the several thousand counter protesters expected to attend. (According to one estimate, the number of counter protestors is expected to be somewhere in the neighborhood of 30,000. The "free speech rally" organizers received a permit for 100 people.) The Boston Police Department is deploying more than 500 police officers, including undercover agents, and some will be wearing body cameras. They have also fenced off a portion of the common to keep the rally separate with the hope of tamping down any potential violence.
Mayor Marty Walsh urged people to stay away from the common because he didn't want large crowds urging fights. “If you’re coming into town tomorrow, please respect the city,” Walsh told WGBH News. “Children watch the actions of adults, so whatever happens tomorrow, children in our city and in our state will be watching your actions, so make sure they’re positive.”
This post has been continually updated throughout the day to reflect the changing nature of the event.