A smaller number remained in the streets when the city curfew went into effect at 10 p.m., CNN reporters in Baltimore said. Some protesters were arrested a brief time later, CNN's Nick Valencia said.
Community members had urged the curfew, which has started Tuesday night, be ended.
"For five days now people have been under curfew," said Jay Morrison of the YMC Community Coalition. "I think we need to put trust in the people. This curfew should be lifted."
Brandon Scott, a Baltimore City Council member, predicted people would defy the curfew as they have in past nights. Police detained 53 people late Friday, including 15 who violated curfew.
Scott said he opposed the curfew extension, partly because of its economic impact.
"We could have seen some businesses recoup some money with the fight parties," he said, referring to Saturday night's boxing match between Manny Pacquiao and Floyd Mayweather.
The announcement about the curfew was made less than three hours before the 10 p.m. to 5 a.m. measure went into effect.
"We have had several good days, peaceful days," Maryland State Police Commissioner William Pallozzi said at a press conference. "We just ask for patience as we move forward."
Maryland National Guard Gen. Linda Singh said she's eager to send troops under her command back home.
"I want to make sure we can close out tonight in a safe, peaceful ... manner," she said. "My focus is ensuring we keep everything in a safe manner ... and we the military will pull out in the same manner we pulled in ... very calm."
Earlier Saturday, marchers converged on Baltimore City Hall after trekking from the Gilmore Homes housing project, where Gray was arrested, as similar gatherings were set for various cities from Boston to Beverly Hills.
Marchers -- some carrying signs with messages such "Justice for Freddie Gray" and "It is right to rebel" -- moved peacefully through the streets of Baltimore to War Memorial Plaza outside City Hall, where hundreds of others gathered for the block-party-like rally.
Daisy Villalobos, wearing a T-shirt with the words "Black Lives Matter," traveled from New York, where she said she was hurt earlier this week during an arrest at a Freddie Gray protest in Union Square. The march was about more than police brutality, she said, adding that people were also rallying in support of "neglected communities" throughout the country.
Outside City Hall, a biracial couple -- Devan Sutherland and Joe Savage -- attended the rally with their 7-year-old son Liam.
"It means everything to me and my family," Sutherland said about being at the rally. "I was born and raised here. I care a lot about my city. I love my city ... I decided to stay and raise my family here. And to have a little boy, it's even more important for me to be here."
The Rev. Alvin Gwynn, pastor of Leadenhall Baptist Church, noted the importance of voter registration drives at the massive gathering.
"Those are the people in the jury box," he said.
The rally, organized by the Washington-based Black Lawyers for Justice, came after a week of demonstrations, some of them marred by incidents of arson and looting.
"It's sad it had to come to this -- burning down places that people are going to need," said Baltimore resident Aaron Cook, standing outside a CVS drugstore that was looted and burned this week. "Hopefully we get results from this -- start treating us like we matter."
National Guard troops and police stood in place near the plaza but the scene was starkly different from violent clashes between officers and protesters earlier this week.
"What really touched me was hearing the youth speak and telling America that they are not thugs," demonstrator Daudi Henderson said. "We can't demonize the victim."
One rally speaker was an uncle of Oscar Grant, a 22-year-old African-American who was unarmed when he was fatally shot by a police officer on a train station platform in Oakland, California. Protests erupted in the city after a white transit police officer was convicted in 2010 of involuntary manslaughter, not murder.
Another speaker, Tanaira Cullens, 24, said she is working on a master's degree from Johns Hopkins University.
"It's important that we stand together not just as black people, but black people and their allies to do great ... and positive things in our community," she told CNN.
Cullens, who was raised in the same neighborhood as Freddie Gray, said it's "essential for children to be able to rise above their circumstances."
"I was blessed because my parents are educated people," she said. "My father works with people who are having a change of life. They are coming from negative backgrounds and he brings them around to do positive things in their community. My mother is a professor. So I was raised to value my education. And so many people don't have that opportunity."
After the rally, hundreds of people marched from City Hall to the boarded-up CVS store near the corner of Pennsylvania and North avenues.
Gov. Larry Hogan urged protesters to remain peaceful and nonviolent.
"The right to demonstrate is a fundamental part of our society, but damaging property or putting innocent bystanders in danger will not be tolerated," he said.
In response to the unrest earlier in the week, Logan said 3,000 National Guard troops, 578 state troopers and 432 law enforcement officers from Pennsylvania and New Jersey were deployed throughout the city.
Early Saturday, protesters cleared the streets to observe a curfew. A few demonstrators scuffled with police after 10 p.m. Friday, when the curfew went into effect.
Authorities used a megaphone from a helicopter to warn protesters to go home or get arrested.
By midnight, the streets were deserted as a hush washed over Baltimore's streets, a far cry from the boisterous honking, weeping and cheers
earlier when the city's top prosecutor announced charges.
City prosecutor identifies six officers
Six police officers were charged in the death of Gray, Baltimore City State's Attorney Marilyn Mosby
said Friday, describing what she believes happened April 12, when Gray was arrested.
The 25-year-old died after suffering "a severe and critical neck injury" while being transported "handcuffed, shackled by his feet and unrestrained" inside a police van, she said. It is against police policy to transport a prisoner without proper restraints such as a seat belt.
The police union called for an independent prosecutor, saying Mosby has conflicts of interests. They also criticized her for not waiting until police were done with their inquiry.
"Let me begin by stating how appalled and frustrated we are at this morning's events. .... We are disappointed in the apparent rush to judgment given the fact that the investigation into this matter has not been concluded," said Gene Ryan, president of the police union. "Our officers, like every other American, are entitled to due process."
The Baltimore Fraternal Order of Police said the officers did nothing wrong.
"No officer injured Mr. Gray, caused harm to Mr. Gray, and they are truly saddened by his death," said Michael Davey, an attorney for the union.
The officers face various charges that could lead to decades in prison.
• Officer Caesar R. Goodson Jr., 45, faces one count of second-degree depraved-heart murder, involuntary manslaughter, second-degree assault, manslaughter by vehicle (gross negligence), manslaughter by vehicle (criminal negligence) and misconduct in office.
• Lt. Brian W. Rice, 41, faces one count of involuntary manslaughter, two counts of second-degree assault, two counts of misconduct in office and one count of false imprisonment.
• Sgt. Alicia D. White, 30, faces one count of involuntary manslaughter, second-degree assault and misconduct in office.
• Officer William G. Porter, 25, faces one count of involuntary manslaughter, second-degree assault and misconduct in office.
• Officer Garrett E. Miller, 26, faces two counts of second-degree assault, two counts of misconduct in office and one count of false imprisonment.
• Officer Edward M. Nero, 29, faces two counts of second-degree assault, two counts of misconduct in office and one count of false imprisonment.
Second-degree depraved-heart murder is punishable by up to 30 years in prison.
Gray's relatives said they are satisfied with the charges announced.
"These charges are an important step in getting justice for Freddie," said his stepfather, Richard Shipley.
Out on bail
Court records show the officers have paid bail, which for Goodson, White, Porter and Rice had been set at $350,000 each; for Nero and Miller it was $250,000 apiece.
The six have a preliminary hearing on May 27.
Mayor Stephanie Rawlings-Blake called for the immediate suspension of all the officers facing charges.
Police officers arrested Gray on April 12. He slipped into a coma after suffering a series of injuries and died a week later.
Mosby said the incident began when two police officers on bike patrol "made eye contact" with Gray, who then ran.
When officers caught up to him, he surrendered and was placed on the ground, arms handcuffed behind his back. He said he couldn't breathe and asked for an inhaler, but he did not get it, according to Mosby.
Although police found a knife in Gray's pants, it was a variety allowed by Maryland law, and police had no reason to detain him, the prosecutor said.
Still, they called for a police transport van and loaded Gray, in handcuffs, into the van. They did not put a seat belt on him, Mosby said.
Goodson stopped the vehicle four times over the course of the approximately 40-minute ride to the police station. At the first stop, officers took Gray out, put shackles on his ankles and placed him -- still handcuffed -- headfirst and on his stomach in the back.
At the last stop, Goodson picked up another man who was put in the back of the van on the other side of the partition that keeps prisoners separated.
Mosby said the officers were "grossly negligent" for failing to get Gray medical help, despite his requests, until arrival at the Western District Police Station.
By then, he was no longer breathing, she said.
Gray was rushed to a hospital, where he underwent surgery.
He died a week later.