Much of downtown Washington was sealed off yesterday, and the White House was fortified as thousands descended on the US capital. Authorities estimated that the march would attract up to 200,000 people.
It was only one of hundreds of protests across the world, sparked off by the US police killing of George Floyd. Mr Floyd, 46, died in Minneapolis on May 25 while handcuffed - as Derek Chauvin, a white police officer, knelt on his neck for nearly nine minutes as he pleaded, "I can't breathe". Chauvin has been charged with murder.
The initial focus of protesters had been the arrest and charging of all four officers involved in death of Floyd, not just Chauvin. But campaigners said the killing of George Floyd was not just a case of a few bad apples in the police force, but rather an insight into a criminal justice system riven by systemic racism. The way in which police forces were recruited, governed and regulated needed to be completely overhauled, said protesters. Campaigners said an attendant problem has been the increased militarisation of the police, often with small forces purchasing armoured vehicles designed for the armed forces.
The evidence of police malfeasance has been widespread. As the demonstrations spread to dozens of other cities, police officers have been filmed assaulting peaceful protesters, often in a manner that echoed the aggression shown during the arrest of Floyd.
In Buffalo, New York, two police officers were charged with assault after a video showed them shoving over a 75-year-old protester who fell and suffered a head injury. All 57 members of their police tactical unit quit their roles in protest at the decision to charge their colleagues.
In Indianapolis, a video emerged showing four officers hitting a woman with batons. New York suspended an officer who pulled down a protester's face mask and pepper sprayed him.
The blatant police aggression on peaceful protesters has had an effect.
Amid a flurry of reforms across the US, Democrat leaders in Minneapolis voted to end the use of knee restraints and chokeholds by officers. And a judge in Denver ordered the city's police to stop using tear gas, plastic bullets and flash grenades.
US District Judge Brooke Jackson said: "These are peaceful demonstrators, journalists, and medics who have been targeted with extreme tactics."
Seattle banned use of CS gas by officers for 30 days. And Los Angeles Mayor Eric Garcetti, a Democrat, said he planned $150m in cuts to the LA Police Department.
Calls to "defund the police," including cutting the New York Police Department's $6bn budget, became a rallying cry for some protesters.
Donald Trump - picking up the possibility of portraying himself as the "law and order" candidate in the upcoming US presidential election, wrote on Twitter: "Biden wants to Defund the Police!"
Biden on Friday condemned Trump as "frankly despicable" for suggesting George Floyd would have thought new jobs figures represented a "great day" for America.
But yesterday was the day of protest, and marches were held in many US cities including Philadelphia and Miami - where about 100 protesters gathered at President Donald Trump's golf resort.
Marchers were also out in Australia, Germany, Japan, South Korea, Belgium, and even Iraq. In Sydney, aboriginal protesters performed a traditional smoking ceremony at a Black Lives Matter protest, and 30,000 people gathered in Brisbane.
Yassin Alaa, 20, a protester in Baghdad, said: "I think what the Americans are doing is brave and they should be angry - but rioting is not the solution."
Thousand of people gathered in Dublin and Belfast, and in many other Irish cities in peaceful protest - however in Northern Ireland, police said they had issued "a significant number" of fines given the dangers of crowds in the pandemic.
Meanwhile in Britain the biggest protests were seen in London, where tens of thousands demonstrated against the brutal killing of George Floyd - despite police and ministers urging people to stay away for fear of spreading Covid-19.
Protesters in Parliament Square went down on one knee while raising one fist in the air, before crowds began to chant "no justice, no peace" and called out George Floyd's name.
The crowds also voiced anger at the ubiquity of racist violence throughout society and at all discrimination.
The vast majority of the day's protests were peaceful, but later in the evening, as demonstrators dispersed in London, there were disturbances outside Downing Street.
Police in the German city of Hamburg also used pepper spray on protesters as some demonstrations against police brutality turned ugly.
US health experts warned this weekend's protests could lead to a surge in coronavirus cases.
Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said: "It is the perfect set up for the spread of the virus. It's a delicate balance because the reasons for demonstrating are valid, and yet the demonstration itself puts oneself at an additional risk."