The United Auto Workers (UAW) formally endorsed Joe Biden’s re-election campaign on Wednesday 24 January.
The endorsement comes after months of speculation over whether the powerful auto union would stand behind the 46th president.
“Joe Biden bet on the American worker while Donald Trump blamed the American worker,” UAW president, Shawn Fain, told the conference.
“If our endorsement must be earned, Joe Biden has earned it.”
Mr Biden last year became the first US president to walk a picket line when he joined striking autoworkers outside a Michigan auto plant.