Just over a year after Donald J. Trump descended his iconic escalator in Manhattan to announce he was joining a packed field of political veterans seeking the Republican nomination for president, the New York billionaire completed an astonishing and historic political ascent Thursday night in Cleveland, officially claiming his party’s nomination — and declaring to struggling Americans, “I am your voice.”

Trump electrified the convention crowd on closing night, with chants of “U.S.A.” frequently breaking out as the nominee vowed to put “America first.” He used the speech to align his campaign squarely on the side of struggling American workers of all political stripes, as he moved to broaden his appeal beyond the Republican base that largely decided the primaries.

“Every day I wake up determined to deliver for the people I have met all across this nation that have been ignored, neglected and abandoned. … These are people who work hard but no longer have a voice,” Trump said. “I am your voice.”

And he delivered a tough law-and-order message throughout, declaring from the convention floor in Cleveland, “Safety will be restored” under a Trump presidency.