The city’s 91-year succession of Irish American and Italian American mayors has ended, with Michelle Wu earning one of two spots in the general election in November.

BOSTON — Michelle Wu, an Asian American progressive who has built a campaign around climate change and housing policy, earned one of two spots in Boston’s preliminary mayoral election on Tuesday, setting the stage for change in a city that for nearly 200 years has elected only white men.

The daughter of Taiwanese immigrants, she is not from Boston, and has built an ardent following as a city councilor by proposing sweeping structural changes, like making the city’s public transportation free, restoring a form of rent control, and introducing the country’s first city-level Green New Deal.

But another city councilor, Annissa Essaibi George, announced that she had won the other spot in November’s general election, and her two closest competitors told supporters they had lost.

For weeks, polls showed two leading Black candidates — Acting Mayor Kim Janey and City Councilor Andrea Campbell — in a dead heat with Ms.

The prospect of a general election with no Black candidate came as a bitter disappointment to many in Boston, which had seemed closer than ever before to electing a Black mayor.

Essaibi George, who grew up in Dorchester, the daughter of Tunisian and Polish immigrants, and is the only candidate to oppose cuts to the police budget and favor increasing the number of officers on Boston streets.

“The mayor of Boston cannot make the T free.

The mayor of Boston cannot mandate rent control.

Essaibi George’s supporters, who gathered on a Dorchester street corner on the eve of the election, wearing her campaign’s trademark hot pink T-shirts, were mostly white, and named public safety as a top concern.

“It’s all great, though the socialism aspect of it kind of scares me a little bit,” he said, noting that several of his relatives are Boston police officers.

Its manufacturing jobs have mostly vanished, making way for affluent, better-educated newcomers, “people who may read The Times but don’t necessarily go to church,” said Larry DiCara, 72, a former Boston city councilor.

Wu entered the City Council in 2014, the body had largely concerned itself with constituent services, but over the next few years it became a platform for national-level policy, on climate change and police reform.

Wu’s policy platform will be enough to carry her through the general election in November.

“People just want the city to work for them, they don’t want nice policies,” said Kay Gibbs, 81, who worked as a political aide to Thomas Atkins, the city’s first Black city councilor, and to Representative Barney Frank.

Boston’s next mayor, she said, will have her hands full with the basics, taking control of powerful forces within a sprawling city government.

Janey, who was then the City Council president, became acting mayor in March after Martin J

Walsh became the country’s labor secretary, and many assumed she would cruise into the general election

Janey said incumbency had not necessarily proved an advantage