The diverse group of protesters also chanted “seven bullets, seven days” — a reference to the number of times Mr Blake was shot last Sunday — as they marched toward the courthouse in Kenosha.
Meanwhile authorities in Portland, Oregon have said one person has been fatally shot during clashes between supporters of President Trump and counter-protesters.
It was not clear if the shooting was linked to fights that broke out as a caravan of about 600 vehicles was confronted by protesters in the city’s downtown.
“Portland Police officers heard sounds of gunfire from the area of Southeast 3rd Avenue and Southwest Alder Street,” the Portland Police Bureau said in a statement.
“They responded and located a victim with a gunshot wound to the chest. Medical responded and determined that the victim was deceased.”
The caravan of Mr Trump’s supporters had gathered earlier in the day at a nearby mall and drove as a group to the heart of Portland.
As they arrived in the city, protesters attempted to stop them by standing in the street and blocking bridges.
Videos from the scene showed sporadic fighting, as well as the president’s supporters firing paintball pellets at opponents and using bear spray as counter-protesters threw things at the caravan.
Earlier in Kenosha, Mr Blake’s father, Jacob Blake Sr, gave an impassioned call for changing a system he described as fostering police brutality and racial inequities.
A political rally is caravanning throughout downtown Portland. There have been some instances of violence between demonstrators and counterdemonstrators. Officers have intervened and in some cases made arrests.
Advertisement— Portland Police (@PortlandPolice) August 30, 2020
“There were seven bullets put in my son’s back. Hell yeah, I’m mad,” Mr Blake Sr said.
“What gave (the police) the right to attempted murder on my child? What gave them the right to think that my son was an animal? What gave them the right to take something that was not theirs? I’m tired of this.”
Kenosha police officer Rusten Sheskey and two other officers were responding to a domestic abuse call last Sunday when Mr Sheskey shot Mr Blake in the back.
Mr Blake Sr told reporters on Saturday that his son is heavily sedated, but has regained consciousness.
“He’s in a lot of pain,” he said.
“I just wish I could pick my baby up and make it all right.”
He called for Mr Sheskey to be charged and for the other two officers at the scene to be fired.
Several of Saturday’s speakers encouraged the crowd to vote for change in November, and to push for changing legislation in Wisconsin that would lead to police reform.
One of Mr Blake’s sisters, Letetra Widman, said she felt recharged “to stand up not just for Jacob, but for all the people who have not gotten justice.”
Captured on cellphone video, the shooting sparked new protests against racial injustice and police brutality months after George Floyd’s death touched off a wider reckoning on race.
Protesters have marched in Kenosha every night since Mr Blake’s shooting, with some protests devolving into unrest with damage to buildings and vehicles.
On Tuesday, two people were killed by an armed civilian.
The commander of the National Guard said on Friday that more than 1,000 Guard members had been deployed to help keep the peace, with more on the way.
President Donald Trump will visit Kenosha on Tuesday to meet with law enforcement and survey damage from recent demonstrations that turned violent, White House spokesman Judd Deere told reporters travelling with the president on Saturday night.
