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 and thanked him for his service. 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.
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.
In an opinion piece written for CNN in August 2017 while serving as a commentator for the network, Whitaker, a former U.S. attorney, said Mueller would be crossing a line if he investigated the Trump family's finances.
Republicans had repeatedly urged Trump not to oust Sessions, a conservative Republican former senator from Alabama, before the elections lest it create political fallout. They also argued that Sessions should be allowed a graceful exit after he doggedly carried out Trump's agenda on illegal immigration and other administration priorities.
RECUSAL OVER RUSSIA
Trump was only a few weeks into his presidency in March 2017 when Sessions upset him. Rejecting White House entreaties not to do so, Sessions stepped aside from overseeing the Federal Bureau Investigation's probe of potential collusion between the Trump presidential campaign and Moscow. Sessions cited news reports of previously undisclosed meetings he had with Russia's ambassador to Washington as his reason for recusal.
Deputy Attorney General Rod Rosenstein took over supervision of the Russia investigation and in May 2017 appointed Mueller as the Justice Department's special counsel to take over the FBI's Russia probe after Trump fired FBI Director James Comey. Rosenstein also has faced criticism from Trump.
A permanent replacement for Sessions must be confirmed by the U.S. Senate, which Trump's Republicans will continue to control as a result of Tuesday's midterm elections.
Mueller is pursuing a wide-ranging investigation into whether Trump's campaign colluded with Russia, whether Trump unlawfully tried to obstruct the probe, and financial misconduct by Trump's family and associates. Mueller has brought charges against Trump's former campaign chairman and other campaign figures, as well as against 25 Russians and three firms accused of meddling in the campaign to help Trump win.
Trump has denied his campaign colluded with Russia.
Trump publicly seethed over Sessions' recusal and said he regretted appointing him. On Twitter he blasted Sessions as "VERY weak" and urged him to stop the Russia investigation. In July 2017 he told the New York Times that if he had known Sessions would recuse himself, he never would have appointed him attorney general.
Washington Post journalist Bob Woodward wrote in his book "Fear" that Trump, talking to a White House secretary, disparaged Sessions as "mentally retarded" and a "dumb Southerner" while mocking his accent.
There were news reports in the weeks after Mueller's appointment that Sessions had offered to resign. Sessions usually remained quiet on Trump's criticism, but defended himself in February 2018 after a Trump tweet criticizing his job performance by saying he would perform his duties "with integrity and honor."
RESPONDING TO TRUMP
In August, Sessions punched back harder after Trump claimed in a Fox News interview that Sessions "never took control of the Justice Department." Sessions issued a statement saying he "took control of the Department of Justice the day I was sworn in" and vowed not to allow it to be "improperly influenced by political considerations."
As for his own involvement with Russia, Sessions was questioned in January by Mueller's team and has offered shifting public accounts. He has said nothing improper transpired in his meetings during the campaign with Ambassador Sergei Kislyak. In congressional testimony in November, he said he now recalled a meeting during the 2016 campaign in which a campaign adviser, with Trump present, offered to use connections with Moscow to arrange a meeting between Trump and Russian President Vladimir Putin.
Despite Trump's criticism, Sessions has aggressively carried out the administration's conservative policies. Before becoming a senator, he was a hard-charging prosecutor known for a get-tough-on-crime approach and at the Justice Department he made combating drugs, violent crime and illegal immigration top Justice Department priorities.
He sought to strip federal funding from so-called sanctuary cities and states, typically governed by Democrats, that he accused of sheltering illegal immigrants from deportation. His lawsuit against California prompted its governor to accuse the administration of declaring war on the most populous U.S. state.
Sessions announced Trump's decision to rescind protections for young adults brought into the country illegally as children. He backed Trump's ban on people from several Muslim-majority countries from entering the United States.
Sessions also gave prosecutors a greenlight to aggressively enforce federal laws against marijuana in states where it has been decriminalized and moved to curtail the rights of transgender students. (Reporting by Sarah N. Lynch Writing by Bill Trott Editing by Will Dunham and Howard Goller)
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)