Sessions' departure was widely expected to come soon after Tuesday's congressional elections in which Republicans retained their majority in the Senate but lost control of the House of Representatives.
Never in modern history has a president attacked a Cabinet member as frequently and harshly in public as Trump did Sessions, 71, who had been one of the first members of Congress to back his presidential campaign in 2015.
Trump announced Sessions' departure on Twitter. Sessions said in a letter to Trump he resigned at the president's request. Sessions' chief of staff, Matthew Whitaker, will be acting attorney general, Trump said on Twitter.
We are pleased to announce that Matthew G. Whitaker, Chief of Staff to Attorney General Jeff Sessions at the Department of Justice, will become our new Acting Attorney General of the United States. He will serve our Country well....
— Donald J. Trump (@realDonaldTrump) November 7, 2018
Sessions departs as the nation's top law enforcement officer while Special Counsel Robert Mueller, operating under the auspices of the Justice Department, pursues a wide-ranging Russia investigation that already has yielded a series of criminal charges against several of Trump's associates and has dogged his presidency.