The Democratic-controlled Congress has handed President Barack Obama a major legislative victory - extending health care to tens of millions of uninsured Americans and cracking down on insurance company abuses, a climactic chapter in the century-long quest for near universal coverage.
Widely viewed as dead two months ago, the Senate-passed bill cleared the House on a 219-212 vote, with Republicans unanimous in opposition.
Congressional officials said they expected Obama to sign the bill as early as Tuesday (local time) and was expected to make a statement following the vote.
Republicans hoped that by blocking the legislation, they would be able to thwart Obama's ambitious domestic agenda, including immigration reform and climate change legislation.
While national health care has been a goal of presidents stretching back decades, it has proved elusive, in part because self-reliance and suspicion of a strong central government remain strong in the US.
After more than a year of political combat - certain to persist into the fall election campaign for control of Congress - debate on the House floor fell along predictable lines.
"We will be joining those who established Social Security, Medicare and now, tonight, health care for all Americans," said Speaker Nancy Pelosi before the vote, referring the government's pension program and health insurance for the elderly established nearly 50 years ago.
"This is the civil rights act of the 21st century," added Rep. Jim Clyburn of South Carolina, the top-ranking black member of the House.
Republicans readily agreed the bill would affect everyone in America, but warned repeatedly of the burden imposed by more than US$900 billion in tax increases and Medicare cuts combined.
"We have failed to listen to America," said Rep. John Boehner, leader of a party that has vowed to carry the fight into the fall's midterm elections for control of Congress.
Earlier in the day, the House argued its way through a thicket of Republican objections toward an evening vote on the bill to extend coverage to 32 million Americans who lack it, ban insurers from denying coverage on the basis of pre-existing medical conditions and cut deficits by an estimated US$138 billion over a decade.
A shouting band of protesters outside the Capitol dramatised their opposition, and one man stood up in the House visitor's gallery shouting, "Kill the bill" before he was ushered out - evidence of the passions the yearlong debate over health care has stirred.
Obama lobbied by phone from the White House, then took the crucial step of issuing an executive order that satisfied a small group of Democrats who demanded that no federal funds be used for elective abortions.
Over and over, Democrats stressed the historic nature of the day. The measure represents the biggest expansion of the social safety net since Medicare and Medicaid were enacted in 1965 during President Lyndon B. Johnson's administration to provide government-funded health care coverage to the elderly and poor.
"Health care isn't only a civil right, it's a moral issue," said Democratic Rep. Patrick Kennedy. He said his late father, Sen. Edward M. Kennedy, had worked his entire career for nationwide health care, and President John F. Kennedy before him.
Obama has said often that presidents of both parties have tried without success to achieve national health insurance, beginning with Theodore Roosevelt early in the 20th century.
The 44th president's quest to succeed where others have failed seemed at a dead end two months ago, when Republicans won a special election to fill Edward Kennedy's Massachusetts Senate seat, and with it, enough votes to prevent a final vote.
But the White House, Pelosi and Senate Majority Leader Reid soon came up with a rescue plan that required the House to approve the Senate-passed measure despite opposition to many of its provisions, then have both chambers pass a fix-it measure incorporating numerous changes.
Under the legislation, most Americans would be required to purchase insurance, and face penalties if they refused. Much of the money in the bill would be devoted to subsidies to help families at incomes of up to US$88,000 a year pay their premiums.
The legislation would also usher in a significant expansion of Medicaid, the federal-state health care program for the poor.
The insurance industry would come under new federal regulation. They would be forbidden from placing lifetime dollar limits on policies, from denying coverage because of pre-existing conditions and from cancelling policies when a policyholder becomes ill.
Parents would be able to keep older children on their coverage up to age 26. A new high-risk pool would offer coverage to uninsured people with medical problems until 2014, when the coverage expansion goes into high gear.
Once enacted, the two bills would create a series of so-called "insurance exchanges" beginning in 2014 where self-employed people and small businesses could pool together to shop for health care coverage.
To pay for the changes, the legislation includes more than US$400 billion in higher taxes over a decade, roughly half of it from a new Medicare payroll
tax on individuals with incomes over US$200,000 and couples over US$250,000.
AP