The law, which has been denounced by Democrats and voting rights groups, comes as Republican-controlled legislatures across the country mount the most extensive contraction of ballot access in generations.

Georgia Republicans on Thursday passed a sweeping law to restrict voting access in the state, introducing more rigid voter identification requirements for absentee balloting, limiting drop boxes and expanding the Legislature’s power over elections. The new measures make Georgia the first major battleground to overhaul its election system since the turmoil of last year’s presidential contest.

The legislation, which followed Democratic victories that flipped the state at the presidential and Senate levels, comes amid a national movement among Republican-controlled state legislatures to mount the most extensive contraction of voting access in generations. Seeking to appease a conservative base that remains incensed about the results of the 2020 election, Republicans have already passed a similar law in Iowa, and are moving forward with efforts to restrict voting in states including Arizona, Florida and Texas.

Democrats and voting rights groups have condemned such efforts, arguing that they unfairly target voters of color. They say the new law in Georgia particularly seeks to make voting harder for the state’s large Black population, which was crucial to President Biden’s triumph in Georgia in November and the success of Senators Raphael Warnock and Jon Ossoff in the January runoff elections.

Mr. Biden joined Georgia Democrats on Thursday in denouncing efforts to limit voting, calling Republicans’ push around the country “the most pernicious thing.”

“This makes Jim Crow look like Jim Eagle,” he said at his first formal news conference since taking office.

Though the law is less stringent than the initial iterations of the bill, it introduces a raft of new restrictions for voting and elections in the state, including limiting drop boxes, stripping the secretary of state of some of his authority, imposing new oversight of county election boards, restricting who can vote with provisional ballots, and making it a crime to offer food or water to voters waiting in lines. The law also requires runoff elections to be held four weeks after the original vote, instead of the current nine weeks.

The law does not include some of the harshest restrictions that had been proposed, like a ban on Sunday voting that was seen as an attempt to curtail the role of Black churches in driving turnout. And the legislation now, in fact, expands early voting options in some areas. No-excuse absentee voting, in which voters do not have to provide a rationale for casting a ballot by mail, also remains in place, though it will now entail new restrictions such as providing a state-issued identification card.

State Representative Alan Powell, a Republican, spoke in favor of the voting bill on Thursday.
Alyssa Pointer/Atlanta Journal-Constitution, via Associated Press

The law passed the Georgia House on Thursday morning by a party-line vote of 100 to 75, and was approved by the Senate in the evening on a 34-to-20 vote before being signed by Gov. Brian Kemp, a Republican.

In brief remarks on Thursday evening, Mr. Kemp said the drafting of the bill had started after the 2020 election.

“We quickly began working with the House and Senate on further reforms to make it easier to vote and harder to cheat,” he said. “The bill I signed into law does just that.”

The governor, who is up for re-election in 2022 and was heavily criticized by Donald J. Trump after the election for not abetting the former president’s effort to subvert the outcome, detailed his own history as a secretary of state fighting for stronger voter identification laws, which Democrats have denounced as having an outsize impact on communities of color. Mr. Kemp said that protests against the bill were pure politics.

“I fought these partisan activists tooth and nail for over 10 years to keep our elections secure, accessible and fair,” Mr. Kemp said.

Georgia has quickly become fiercely contested political territory, and a focal point of the continuing clashes over voting rights. During the contentious months after the November election, the state became a particular obsession of Mr. Trump, who spun falsehoods, lies and conspiracy theories about electoral fraud and pressured election officials, including the Republican secretary of state, to “find” him votes.

Yet after election officials rebuffed Mr. Trump, and multiple audits reaffirmed the results, Republican legislators held hearings on the election, inviting some of the president’s allies like Rudolph W. Giuliani to speak. After the hearings, G.O.P. lawmakers promised to introduce new legislation to help “restore confidence” in elections, even though the last one had been held safely and securely.

Outside the Statehouse in Atlanta on Thursday, a coalition of Black faith leaders assembled a protest, voicing their opposition to the bill and calling for a boycott of major corporations in Georgia that they said had remained silent on the voting push, including Coca-Cola.

The faith leaders also sought a meeting with Mr. Kemp and Lt. Gov. Geoff Duncan, also a Republican. Mr. Duncan met with the group for three minutes; Mr. Kemp did not.

“I told him exactly how I felt: that these bills were not only voter suppression, but they were in fact racist, and they are an attempt to turn back time to Jim Crow,” said Bishop Reginald T. Jackson, who oversees all African Methodist Episcopal churches in the state.

The voting legislation’s approval in the House on Thursday morning came after an impassioned debate on the floor of the chamber.

Erica Thomas, a Democratic state representative from outside Atlanta, opened her remarks by recalling the memory of former Representative John Lewis of Georgia, the civil rights leader who died last year. She quoted an old speech of his before voicing her opposition to the bill.

“Why do we rally, why do we protest voter suppression?” she said. “It is because our ancestors are looking down right now on this House floor, praying and believing that our fight, and that their fight, was not in vain. We call on the strength of Congressman John Lewis in this moment. Because right now, history is watching.”

Nicole Craine for The New York Times

Other Democrats said the bill was rooted in the election falsehoods that have been spread by Mr. Trump and his allies.

“Where is the need for this bill coming from?” said Debbie Buckner, a Democratic representative from near Columbus. “From the former president who wanted the election fixed and thrown out, even when Georgia leadership told him they couldn’t do it if they wanted to.”

Representative Zulma Lopez, who represents a majority-minority district on the outskirts of Atlanta, said the bill would have an outsize impact on voters of color. In her district, she said, the number of drop boxes would be reduced to nine from 33. This was partly the result, she said, of Democrats’ being excluded from discussions.

“Close to 2.5 million Democrats voted in the general election in 2020,” Ms. Lopez said. “Yet Democrats in this House were left out of any meaningful input into the drafting of this bill.”

Democratic state senators sounded similar alarms during an afternoon debate.

“It is like a Christmas tree of goodies for voter suppression,” said State Senator Jen Jordan, a Democrat from near Atlanta. “And let’s be clear, some of the most dangerous provisions have to do with the takeover of the local elections boards.”

In a sign of the high tensions in Georgia, Mr. Kemp’s speech was abruptly cut off after about 10 minutes. A Democratic state representative, Park Cannon, had tried to attend the signing and remarks, but the doors to the governor’s office were closed.

After officers would not let her enter, Ms. Cannon lightly knocked on the door. Two officers immediately detained her, placing in her handcuffs and escorting her through the State Capitol. Neither Ms. Cannon nor the governor’s office immediately responded to requests for comment.

Alan Powell, a Republican representative from northeastern Georgia, defended the state’s bill, saying it would bring needed uniformity to an electoral system that was pushed to the brink last year.

“The Georgia election system was never made to be able to handle the volume of votes that it handled,” he said. (Multiple audits affirmed the results of Georgia’s elections last year, and there were no credible reports of any fraud or irregularities that would have affected the results.) “What we’ve done in this bill in front of you is we have cleaned up the workings, the mechanics of our election system.”

“Show me the suppression,” Mr. Powell said. “There is no suppression in this bill.”

The law is likely to be met by legal challenges from Democratic groups, and voting rights organizations have vowed to continue to work against the provisions.

Bishop Jackson said he would be working with his constituents to make sure that they had the proper identification, registered in time, and knew how to vote under the new rules.

“This is a fight,” he said. “I think we’re probably at halftime. I think we got another half to go.”

Thomas Kaplan contributed reporting.