Washington — President Biden signed the $1.9 trillion American Rescue Plan Act into law on Thursday, finalizing an early policy victory that will send much-needed aid to millions of Americans still struggling from the COVID-19 pandemic.

“This historic legislation is about rebuilding the backbone of this country and giving people in this nation, working people, middle class folks, people who built the country, a fighting chance,” Mr. Biden said before signing the bill, one day earlier than expected.

The bill was narrowly approved by the House on Wednesday with a vote of 220 to 211, with one Democrat joining all Republicans in voting against it. It passed the Senate on Saturday with a 50 to 49 vote, also along party lines.

President Biden signs the American Rescue Plan on March 11, 2021, in the Oval Office of the White House.

MANDEL NGAN/AFP via Getty Images

Mr. Biden signed the bill hours before delivering his first prime-time national address to mark the one-year anniversary of the COVID-19 pandemic, which has since taken more than 529,000 American lives. The White House said the president and Vice President Kamala Harris will travel to Atlanta next Friday, part of what the White House is calling the “Help is Here” tour to tout the new relief bill in cities around the country.

New CBS News polling shows that the bill is widely popular with the public, with three in four Americans approving of its passage. Two-thirds of Americans also say Mr. Biden is doing a good job in his handling of the pandemic.

The American Rescue Plan provides $1,400 direct payments to individuals making up to $75,000 annually, $350 billion in aid to state and local governments and $14 billion for vaccine distribution. The bill also provides $130 billion to elementary, middle and high schools to assist with safe reopening.

White House press secretary Jen Psaki said the first wave of direct deposit checks would begin hitting Americans’ bank accounts as soon as this weekend.

It includes an additional $300 billion in weekly jobless benefits through September and an expanded tax credit of up to $3,600 per child, initially distributed in monthly installments. The child tax credit could raise 4 million children out of poverty, according to an analysis by the Center on Budget and Policy Priorities.

More than $50 billion will be distributed to small businesses, including $7 billion for the Paycheck Protection Program. The bill also provides $25 billion for relief for small and mid-sized restaurants, which have suffered significantly during the pandemic.

The measure expands eligibility for subsidies to purchase health insurance to people of all incomes under the Affordable Care Act (ACA), a provision that was particularly controversial for Republicans who oppose the bill. It also incentivizes states to expand Medicaid under the ACA by having the federal government pay for new recipients. Several million people could save hundreds of dollars in health care costs once the bill becomes law.