House Judiciary Committee Chairman Jerrold Nadler gavelled in the session, many lawmakers and witnesses masked during the Covid-19 outbreak, as Democrats review the Justice in Policing Act, a far-ranging package of proposals amid a national debate on policing and racial inequity.
Lawmakers also heard testimony from civil rights and law enforcement leaders as Congress considers the changes to police practices and accountability after Floyd's death in police custody and the mass protests that followed.
"Today we answer their call," Nadler said.
House Speaker Nancy Pelosi watched from the hearing audience, and the House GOP leader Kevin McCarthy also joined.
Republicans are criticising activists who want to "defund the police" - a catch-all term for re-imagining law enforcement, but one that US President Donald Trump and his allies have seized on to portray Democrats as extreme as GOP lawmakers rush to come up with their own proposals.
"The American people understand that it's time for a real discussion," said Representative Jim Jordan of Ohio, the ranking Republican on the panel. But he said what they also understand is that "it is pure insanity to defund the police."
For hours, witnesses described what one called a "lynching" over what happened to Floyd on May 25, and others placed his death alongside those of other African Americans that have created a tally becoming difficult for lawmakers in Congress to ignore.
Representative Karen Bass, D, the chair of the Congressional Black Caucus, which is leading the legislative effort, said the proposed changes reflect a nation coming to grips with a history of racial injustice.
"This is about the kind of America we all want to see," said Bass.
The Democrats' legislation would create a national database of police misconduct, ban police choke holds and loosen "qualified immunity" to make it easier for those injured to seek damages in lawsuits, among other changes.
The proposals don't go as far as some activists want to defund police departments by shifting law enforcement resources into other community services. They do, however, make available grant money for states to reimagine ways of policing.
Republicans as well as Democrats have called for a national registry of use-of-force incidents, so police officers cannot transfer between departments without public awareness of their records.
Representative James Sensenbrenner, R, said the "depravity" he said he saw in the video of Floyd's death "burned in my soul." He welcomed a new database and also called for police chiefs to get rid of "bad apples."
There is also bipartisan support for increasing the use of police body cameras, ending no-knock warrants as police used to enter the home of Breonna Taylor who was killed in Louisville, Kentucky, and other changes to police practices and oversight.
Philonise Floyd's testimony captivated the room as he recounted what he saw in the widely viewed video as an officer pressed a knee into George Floyd's neck for more than eight minutes while other police stood by. The one officer is now charged with murder, and three others also face charges.
"He called all of the officers 'sir," said Philonise Floyd. "He still called them 'sir' as he begged for his life."
"His life mattered," the brother said. He broke down as he described George Floyd being treated like an "animal."
Within the wrenching testimony were many of the core issues being debated as part of the police overhaul. Those include questions about whether it's appropriate to have police officers respond to minor offenses - Floyd was accused of passing a counterfeit US$20 bill at a neighbourhood market - and the use of force to detain suspects.
"I am asking you, is that what a black man's life is worth? Twenty dollars?" Philonise Floyd asked.
Millions of people have spilled into city streets in the US and abroad to protest against the death, many embracing the "Black Lives Matter" movement that was launched after the 2014 death of Michael Brown at the hands of police in Ferguson, Missouri. However, the current demonstrations have marked a more diverse, mainstream moment.
"I want America to know, we hear you," said Art Acevedo, the police chief in Houston and president of the Major City Chiefs Association.
The Rev Darrell Scott, who is part of Trump's national diversity coalition, blasted activists' push to dismantle police departments as "one of the most unwise, irresponsible proposals" ever.
Scott noted he, like many black men, has been pulled over by police for "driving while black," as he put it.
"I could very easily have been George Floyd," he testified. "However, I do not recommend throwing out the baby with the bathwater."
The committee also heard from Angela Underwood Jacobs, the sister of a black law enforcement officer, Dave Patrick Underwood, who was shot and killed while guarding a federal courthouse in California during the protests that followed Floyd's death.
Underwood Jacobs, a former Republican candidate for Congress, called for justice for Floyd and also for her brother. She said the idea of defunding the police was "ridiculous."
- AP