The closing marks the latest step in a national movement to improve jail systems and to reverse years of mass incarceration that supporters of the plans say disproportionately affected black and Hispanic people, my colleague Matthew Haag reports.

“For decades, this city and this country’s answer to every societal problem was to throw people in jail,” Corey Johnson, the City Council speaker, said on Wednesday. “Nothing symbolizes those failed policies in this city more than Rikers Island.”

[Read more: N.Y.C. Votes to Close Rikers. Now Comes the Hard Part.]

What’s the plan?

The Rikers complex, which sits in the East River near La Guardia Airport, will be replaced by four smaller jails, one each in Brooklyn, Manhattan, Queens and the Bronx.

Collectively, the jails will hold about 3,300 prisoners daily. Officials say New York’s declining crime rate makes the downsizing from about 7,000 inmates now at Rikers possible. At a peak during the crack epidemic of the 1990s, city jails had nearly 23,000 daily inmates.