When Mr. Buttigieg ended his campaign and endorsed Mr. Biden, the former vice president gave him his own event in Dallas — a favor not afforded to fellow rivals like Ms. Klobuchar and former Representative Beto O’Rourke, who threw their support to Mr. Biden at a campaign rally hours later. Mr. Biden said at the time that Mr. Buttigieg, who was first elected mayor at age 29, reminded him of his son Beau Biden, who died of brain cancer in 2015.
A Navy veteran, Mr. Buttigieg could have led the Department of Veterans Affairs. But Mr. Biden decided instead to put him in charge of transportation, a choice earlier reported by Reuters.
Mr. Buttigieg, whose calling card as a presidential candidate was a claim to have revived his dying hometown, South Bend, made infrastructure — and in particular, the city’s transportation corridors — an early focus of his tenure.
Soon after taking office in 2012, he set about transforming the downtown, the key to which was an initiative he called “Smart Streets.” The existing traffic pattern of multilane, one-way streets whooshed drivers through the city’s retail and office canyons to suburban homes and shopping.
Mr. Buttigieg restored two-way traffic and added bike lanes, trees and on-street parking, all intended to slow traffic and lure pedestrians.
Controversial at first, the $25 million project required dozens of public meetings over two years before residents and the South Bend City Council got on board.
Once completed, the investment ignited a revival of the downtown. New hotels, retail and residential conversions of lofts followed. About 1,000 people had taken up residence in downtown South Bend by the time Mr. Buttigieg left office in January this year, compared with virtually zero when he began.
Mr. Buttigieg would be one of the youngest cabinet members in history. Julián Castro was 39 when Mr. Obama appointed him housing secretary in 2014. Alexander Hamilton was in his mid-30s when he became the nation’s first Treasury secretary.
Trip Gabriel and Michael D. Shear contributed reporting.