Tim Walz accepted the nomination for vice president in a Democratic National Convention speech that blended optimism with fierce critiques of Republican rival Donald Trump.

The Minnesota Governor, little known before his selection by Vice President Kamala Harris, thanked the packed arena in Chicago.

“We’re all here tonight for one beautiful, simple, reason: We love this country,” Mr Walz said. “Thank you for bringing the joy to this fight.”

Mr Walz ran through his career, starting with his work as a high school teacher and coach.

“It was those players and my students who inspired me to run for Congress,” he said. “I learned how to work across the aisle on issues like growing the rural economies and taking care of veterans.

“While other states were banning books from their schools, we were banishing hunger from ours.

“Everybody belongs, and everybody has a responsibility to contribute.”

In introducing himself to voters as Ms Harris’ running mate, Mr Walz has made his family’s struggle with fertility a central part of his narrative, a tangible way to connect with voters alarmed at the erosion of reproductive rights in the US.

“If you’ve never experienced infertility, I guarantee you know someone who has,” he said, his son Gus crying in the crowd in response.

As he wrapped up his speech to wild applause, his walk-off song Rockin’ In The Free World played – Neil Young having signed off on its use after suing Mr Trump for using the song at campaign rallies without permission.

Earlier, former president Bill Clinton denounced Mr Trump as selfish and urged Democrats to back Ms Harris.

“What does her opponent do with his voice? He mostly talks about himself,” he said. “So the next time you hear him, don’t count the lies, count the I’s.

“He’s like one of those tenors opening up before he walks out on stage trying to get his lungs open by saying: ‘me, me, me, me’. When Kamala Harris is president, every day will begin with you, you, you.

“We’ve got a pretty clear choice it seems to me.

“Kamala Harris, for the people. And the other guy who has proved, even more than the first go-around, that he’s about me, myself and I.”

Clinton, who left office more than 23 years ago, cracked jokes about former president Trump’s age — and his own.

“I actually turned 78 two days ago,” Mr Clinton said. “The only personal vanity I want to assert is that I’m still younger than Donald Trump.”

He said President Joe Biden has, like George Washington, enhanced his legacy by deciding to leave office, saying he “healed our sick and put the rest of us back to work”.

Former House speaker Nancy Pelosi also thanked Mr Biden and said “Vice President Harris is ready to take us to new heights”.

She said: “The parable of January 6 reminds us that our democracy is only as strong as the courage and commitment of those entrusted with its care.”

Transportation secretary Pete Buttigieg took shots at Mr Trump’s running mate JD Vance, saying his selection showed the former president was “doubling down on negativity and grievance” in a campaign “summed up in one word: darkness”.

Organisers dubbed Wednesday night “a fight for our freedoms” with the focus on abortion access and other rights key to their campaign against the Republican nominee.

Speaker after speaker argued their party wants to defend freedoms – especially abortion access and voting rights — while Republicans want to take them away.

House Democratic leader Hakeem Jeffries said Mr Biden would go down as one of the “most consequential presidents of all time” while describing Ms Harris as a “courageous leader, a compassionate leader and common-sense leader”.

He likened Mr Trump as “an old boyfriend who you broke up with, but he just won’t go away”.

“He has spent the last four years spinning around the block, trying to get back into a relationship with the American people,” the New York Democrat said. “Bro, we broke up with you for a reason.”

Stevie Wonder implored the crowd to “choose courage over complacency” and vote before performing Higher Ground, while other celebrities on stage included Oprah Winfrey, singer John Legend, actress Mindy Kaling and poet Amanda Gorman.

Representative Pete Aguilar, the highest-ranking Latino in Congress, labelled Mr Trump a threat to the values his immigrant family grew up with in Southern California.

“Only Kamala Harris and Tim Walz will protect the American dream so that every family can earn a living, own a home, and reach their full potential,” Mr Aguilar said.

“This is a vision for America that Donald Trump will never understand. All he knows is chaos and division.”

Mr Trump bashed the convention on Wednesday as a “charade” and noted the fact that he has been a frequent topic of conversation.

He singled out his predecessor Barack Obama for a highly critical speech on Tuesday night, saying he had been “nasty”.

Jon Polin and Rachel Goldberg, the parents of 23-year-old American Hersh Goldberg-Polin taken hostage by Hamas during the October 7 attack on Israel, were greeted with chants of “bring him home” as they appeared on the stage to plead for the release of the dozens of people who continue to be held captive in Gaza.

While much of the focus was on the presidential race, Democratic Congressional Campaign Committee chairwoman Representative Suzan DelBene told the party faithful it was not enough to win the White House.

“A Democratic Congress is how we turn promises into progress,” she said.

Democrats only need to pick up a handful of seats to retake the majority in the House from Republicans.