Former US presidents, celebrities and thousands of members of the public have gathered to honour civil rights leader, the Reverend Jesse Jackson, who died last month.

Former presidents Joe Biden, Barack Obama and Bill Clinton were among those who spoke at a memorial service in Chicago for the activist.

Mourners included former Vice President Kamala Harris, filmmaker Tyler Perry and former basketball star Isiah Thomas. The service also featured performances, including from singer and actress Jennifer Hudson.

Jackson, who worked alongside Martin Luther King Jr, twice ran to be the Democratic nominee for president and founded the Rainbow PUSH coalition, a social justice and civil rights non-profit.

While praising Jackson in his remarks at the service, Obama made a thinly veiled mention of US President Donald Trump. He said, "Each day we wake up to some new assault on our democratic institutions".

He said the late reverend inspired people to take a harder path and called "on each of us to be heralds of change".

Former Vice President Harris received a standing ovation when she spoke at the service. She appeared to take a jab at Trump, saying, "Let me just start out by saying: I predicted a lot of what is happening right now. I hate to say I told you so, but we did see it coming".

But, she added, that she didn't realise they would be tackling this moment without Jackson's guidance.

Calling Jackson "impatient," she noted, "He did not waste time waiting, even when the doors in front of him were barred and bolted, even if those on the other side hesitated or even ignored him. He always devised a way through".

Civil rights leader, the Reverend Al Sharpton, who worked closely with Jackson during the civil rights movement, was also among the speakers.