CHICAGO — As befits the most populous battleground state, Pennsylvania’s delegates to the Democratic National Convention watched from the front of the United Center here as Lt. Gov. Austin Davis, son of a bus driver, touted how quickly Pennsylvania officials got the Fern Hollow Bridge in Pittsburgh and Interstate 95 in Philadelphia repaired — contrasting those accomplishments with former President Donald Trump’s constant promise of “infrastructure weeks” that never developed.

Mr. Davis cited those projects among the accomplishments of President Joe Biden, who signed a bipartisan infrastructure law early in his administration’s tenure, and Vice President Kamala Harris, who will keep on building, he said.

“Right now, we’re repairing roads and bridges across Pennsylvania, including in Pittsburgh, the city of bridges, and Vice President Harris is looking forward,” he said. “She’s committed to keeping our infrastructure safe and modern.”

Mr. Davis’ address was one of several Pennsylvania-related actions on the first day of the convention. Mr. Biden’s daughter, Ashley, mentioned that she was a Philadelphia social worker. Democratic vice presidential nominee Tim Walz made Monday’s Pennsylvania delegation breakfast one of his first stops. Gov. Josh Shapiro addressed two other delegations besides his own and spoke at a Democratic National Committee Labor Council meeting.