Saturday afternoon, after initially issuing a brief denunciation on Twitter, President Trump, speaking at the start of a veterans’ event at his golf club in Bedminster, N.J., again addressed what he described as “the terrible events unfolding in Charlottesville, Virginia.”
In his comments, President Trump condemned the bloody protests, but he did not specifically criticize the white nationalist rally and its neo-Nazi slogans beyond blaming “hatred, bigotry and violence on many sides.”
“It’s been going on for a long time in our country, it’s not Donald Trump, it’s not Barack Obama,” said Mr. Trump, adding that he had been in contact with Virginia officials. After calling for the “swift restoration of law and order,” he offered a call for unity among Americans of “all races, creeds and colors.”
The demonstration, which both organizers and critics had said was the largest gathering of white nationalists in recent years, was organized to protest the planned removal of a statue of Robert E. Lee from a city park that once bore the name of the Confederate general, but was renamed Emancipation Park.
The turmoil in Charlottesville began with a march Friday night by white nationalists on the campus of the University of Virginia and escalated Saturday morning as demonstrators from both sides gathered in the park. Waving Confederate flags, chanting Nazi-era slogans, wearing helmets and carrying shields, the white nationalists converged on the Lee statue and began chanting phrases like “You will not replace us” and “Jews will not replace us.”
Hundreds of counterprotesters — religious leaders, Black Lives Matter activists and anti-fascist groups known as “antifa” — quickly surrounded the crowd, singing spirituals, chanting and carrying their own signs.
The morning started peacefully, with the white nationalists gathering in McIntire Park, outside downtown, and the counterdemonstrators — including Cornel R. West, the Harvard University professor and political activist — gathering at the First Baptist Church, a historically African-American church here. Professor West, who addressed the group at a sunrise prayer service, said he had come “bearing witness to love and justice in the face of white supremacy.”
At McIntire Park, the white nationalists waved Confederate flags and other banners. As a photographer took pictures, one of them, who gave his name only as Ted because he said he might want to run for political office some day, said he was from Missouri, and added, “I’m tired of seeing white people pushed around.”
But by 11 a.m., after both sides had made their way to Emancipation Park, the scene had exploded into taunting, shoving and outright brawling.
Barricades encircling the park and separating the two sides began to come down, and the police temporarily retreated. People were seen clubbing one another in the streets, and pepper spray filled the air. One of the white nationalists left the park bleeding, his head wrapped in gauze.
Declaring the gathering an unlawful assembly, the police had cleared the area before noon, and the Virginia National Guard arrived as officers began arresting some who remained. But fears lingered that the altercation would start again nearby, as demonstrators dispersed in smaller groups.
Within an hour, politicians, including Gov. Terry McAuliffe, a Democrat, and the House speaker, Paul D. Ryan of Wisconsin, a Republican, had condemned the violence.
The first public response from the White House came from the first lady, Melania Trump, who wrote on Twitter: “Our country encourages freedom of speech, but let’s communicate w/o hate in our hearts. No good comes from violence.”
Attorney General Jeff Sessions said Justice Department agents would support local and state officials in an investigation of Saturday’s events.
“This kind of violence is totally contrary to American values and can never be tolerated,” Mr. Sessions said in a statement.
After the rally was dispersed, its organizer, Jason Kessler, who calls himself a “white advocate,” complained in an interview that his group had been “forced into a very chaotic situation.” He added, “The police were supposed to be there protecting us and they stood down.”
The street fights were the latest in a series of tense dramas unfolding across the United States over plans to remove statues and other historical markers of the Confederacy. The battles have been intensified by the election of Mr. Trump, who enjoys fervent support from white nationalists.
Adding to the turmoil, the Federal Aviation Administration said late Saturday that a Virginia State Police helicopter had crashed about seven miles southwest of Charlottesville. State Police officials said two people died in the crash, the cause of which was not known.
Here in Charlottesville, the protest, billed as a “Unite the Right” rally, was the culmination of a year and a half of debate in Charlottesville over the fate of the Lee statue. A movement to remove it began when an African-American high school student here started a petition. The City Council voted 3 to 2 in April to sell it, but a judge issued an injunction temporarily stopping the move.
The city had been bracing for a sea of alt-right demonstrators, and on Friday night, hundreds of them, carrying lit torches, marched on the picturesque grounds of the University of Virginia, founded in 1819 by Thomas Jefferson. The group included prominent white nationalist figures like Richard Spencer and David Duke, a former imperial wizard of the Ku Klux Klan.
“We’re going to fulfill the promises of Donald Trump” to “take our country back,” Mr. Duke told reporters Saturday. Many of the white nationalist protesters carried campaign signs for Mr. Trump.
Mr. Duke strongly criticized Mr. Trump later in the day after the president condemned the violence.
University officials said one person was arrested and charged Friday night with assault and disorderly conduct, and several others were injured. Among those hurt was a university police officer injured while making the arrest, the school said in a statement.
Teresa A. Sullivan, the president of the university, strongly condemned the Friday demonstration in a statement, calling it “disturbing and unacceptable.”
Still, officials allowed the Saturday protest to go on — until the injuries began piling up.
The city of Charlottesville declared a state of emergency around 11 a.m., citing an “imminent threat of civil disturbance, unrest, potential injury to persons, and destruction of public and personal property.”
Governor McAuliffe followed with his own declaration an hour later.
“It is now clear that public safety cannot be safeguarded without additional powers, and that the mostly-out-of-state protesters have come to Virginia to endanger our citizens and property,” he said in a statement. “I am disgusted by the hatred, bigotry and violence these protesters have brought to our state over the past 24 hours.”
The Republican candidate for governor in Virginia, Ed Gillespie, issued his own statement denouncing the protests as “vile hate” that has “no place in our Commonwealth.”
Mr. Ryan agreed. “The views fueling the spectacle in Charlottesville are repugnant,” he said on Twitter. “Let it only serve to unite Americans against this kind of vile bigotry.”