Donald Trump's vice-presidential running mate, U.S. Senator JD Vance, presented himself to the nation on Wednesday night as the son of a forgotten industrial Ohio town, who will fight for the working class if elected in November.

In chronicling his journey from a difficult childhood to the U.S. Marines, Yale Law School, venture capitalism and finally the U.S. Senate, Vance, 39, introduced himself to Americans while using his story to argue that he understands their everyday struggles.

"I grew up in Middletown, Ohio, a small town where people spoke their minds, built with their hands and loved their God, their family, their community and their country with their whole hearts," Vance said at the Republican National Convention in Milwaukee. "But it was also a place that had been cast aside and forgotten by America's ruling class in Washington."

"Career politicians" like President Joe Biden, Vance said, were responsible for trade policies and foreign wars that hurt communities like his.

"President Trump's vision is simple – we won't cater to Wall Street, we'll commit to the working man," he was due to say, according to excerpts released ahead of time. "We won't import foreign labor, we'll fight for American citizens."

In a sign of his potential value to the ticket, he also planned to speak directly to the working and middle classes in Michigan, Pennsylvania and Wisconsin – three Rust Belt swing states likely to decide the November 5 election.

(With input from Reuters)