Police Commissioner William Evans said Friday that 500 officers, some in uniform, others undercover, were deployed to keep the two groups apart on Saturday.
As many people began to disperse, a small number of rowdy protesters came face-to-face with armored officers near Tremont and Boylston Streets.
Later Saturday afternoon, Boston's police department tweeted that protesters were throwing bottles, urine and rocks at them and asked people publicly to refrain from doing so. She carried a poster she'd made that said, "America's strength is its diversity" and "Fake President". "It's not true. A lot of the people down here just love the United States, are here to promote free speech", he said.
Seun Ajewde, 28, an MBA student at Northeastern University, called the march a "pivotal moment" for those who believe in equality.
"While we maintain that every individual is entitled to their freedom of speech and defend that basic human right, we will not be offering our platform to racism or bigotry", the message noted. "And now out here, there's maybe three, four, five thousand of us all unified, different colors, different races, different sexualities, everything".
An estimated 40,000 counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches.
In addition, harsh restrictions were set in place to obtain the permit for Saturday's rally, including a ban against backpacks, sticks, and anything that could be used as a weapon.
"It has been organized under the auspices of the alt lite, which embraces civic nationalism, rather than the alt right, which advocates white nationalism", the ADL said in a blog post. "We don't want you here".
As the country continues to grapple with the unbridled violence of Charlottesville, Va., last weekend, major cities such as Boston, Dallas, New Orleans and others will be the site of major protests today-some under the guise of "free speech", others in defiance of white supremacy and in what organizers are calling "solidarity with Charlottesville".
Among those who were scheduled to speak were Joe Biggs, formerly a writer for the conspiracy-theory website Infowars, and Kyle Chapman, a far-right activist charged with beating counter-demonstrators with a wooden pole during a clash at Berkeley earlier this year, though it is unclear if either man attended. However, the rally dispersed just 45 minutes after it started on Saturday, and it was not immediately clear which speakers had appeared.
Robert Paulson, another free speech rallygoer, said there was definitely a lot of tension.
"I'm a black woman living in Roxbury", Monica Cannon, a Black Lives Matter Boston activist said.