The Senate approved a package of fixes to the health care reform law Thursday, drawing to a close the chamber's year-long effort to overhaul the nation's insurance system.

House Rules Committee Chairwoman Rep. Louise Slaughter, D-N.Y. presides over a meeting of the committee to decide on the rules for the debate of the Health Care Reconciliation Bill on Capitol in Washington, Thursday, March 25, 2010, in Washington. (AP Photo/Manuel Balce Ceneta) But the work isn't done quite yet.

The bill passed 56 to 43, with Vice President Joe Biden presiding over the chamber. Senate Republicans forced a pair of changes to the reconciliation bill overnight, sending it back to the House for a final vote later Thursday.

Democrats believe the minor changes - to language regarding Pell Grants for low-income students - won't derail House passage, meaning that Democrats are set to finally conclude the legislative struggle needed to make health reform a reality.

"We all made history," Sen. Chuck Schumer (D-N.Y.) told a group of Democrats on the floor, as they celebrated the vote. "We could do nothing else."

Three moderate Democrats voted against the reconciliation bill - Nebraska's Ben Nelson and the two senators from Arkansas, Mark Pryor and Blanche Lincoln. Lincoln faces a tough re-election fight this fall. Republican Johnny Isakson of Georgia is ill and wasn't in the chamber.

No Republicans voted for the reconciliation bill, just as no Republican voted for the underlying health reform law. Sen. John McCain (R-Ariz.) criticized the the measure until the end, saying, "It is the most unsavory sausage-making, Chicago-style bill I have ever seen."

He said the GOP mantra would be to "repeal and replace" the bill going forward. "We can't just have the status quo," McCain said.

The vote came as President Barack Obama took the stage in Iowa City, Iowa - his first stop since he signed the legislation Tuesday - hoping to promote the bill to the American public, which polls show is deeply skeptical of reform. He told Republicans he welcomed the chance to debate them on the merits of the plan, particularly if they insist on pressing for a repeal of the law.

"My attitude is: Go for it," Obama said. "If these congressmen in Washington want to come here in Iowa and tell small-business owners that they plan to take away their tax credits and essentially raise their taxes, be my guest."

The reconciliation bill makes a variety of fixes to the health reform legislation, which passed Sunday night in the House. It removed controversial deals like the Cornhusker Kickback and also pushes off implementation of an excise tax on high-cost "Cadillac" health plans until 2018.

The final vote on reconciliation in the Senate came with little drama - but it followed weeks of tough negotiations between House and Senate Democrats over what should be in it, and whether there would be the votes to pass it.

The top leaders in the Senate, Democratic Majority Leader Harry Reid and his counterpart, Republican Sen. Mitch McConnell, worked out a deal in the early morning hours Thursday to hold the vote at 2 p.m. - and it went off on time, with the final outcome not in doubt.

Sen. Robert Byrd (D-W.V.), the longest-serving senator, was wheeled into the chamber by an aide and shook hands with Reid before going to his place and waiting for his name to be called in the roll. There was a humorous moment when Reid's name was called and he said 'no,' before quickly correcting himself. He made the same mistake when the Senate voted on the overall health reform vote, on Christmas Eve. The chamber broke out in laughter.

Senate Republicans found two rules violations in the section of the bill on student loan reform, and Democrats were forced to strike 16 lines of language dealing with Pell Grants.

The House has already passed the reconciliation bill, on Sunday night when it approved the landmark health reform measure. But since the House and Senate must pass identical versions of the reconciliation bill to put the fixes into law, the reconciliation piece must go back to the House for a second vote.

House Speaker Nancy Pelosi (D-Calif.) said her members would approve the package of changes later Thursday and send the measure onto the president.

"Of all the things they could send back, this is the most benign and easily fixed,' Pelosi told reporters Thursday.

The legislative path that brought the Senate to Thursday's vote was tortuous and politically risky.

The Senate spent months trying to write a bill that could win 60 votes. Democrats succeeded on Christmas Eve, only to lose their filibuster-proof majority a month later.

The White House and congressional leaders revived the bill after deciding on a two-step process - the House passing the Senate bill, followed by both chambers using fast-track rules known as reconciliation to pass a package of fixes. This was the only way House members would agree to approve the Senate bill, and the only way the Senate could make changes that the House wanted.

Reconciliation was fraught with challenges. But Democrats successfully scrubbed the bill of any potential procedural landmines, preventing Republicans from stripping out any major policy pieces that would have endangered its passage in the House or the Senate.

Democrats also held together during the more than 13 hours of amendments, turning each one back. While Republicans implored their colleagues to make changes, Democrats argued that any changes would send the bill back to the House for another vote, an outcome they worked mightily to avoid before the parliamentarian's ruling early Thursday. That meant Democrats had to vote against such campaign ad fodder as a provision barring sex offenders from being given Viagra.

Once Republicans struck two minor provisions from the bill, sending it back to the House, some liberals suggested that Democrats had one last chance to fight for the public option. But no senators took the bait.

Democrats insisted on keeping the bill as clean as possible so the House can give the measure swift approval - and that the party can be done with the health care debate once and for all.

Sen. Bernie Sanders (I-Vt.), a leading proponent of a public option, shook his head Thursday morning when asked whether he'd offer the proposal as an amendment to the reconciliation bill.

Senate Budget Chairman Kent Conrad (D-N.D.) said: "Everybody feels committed, feels we've done the right thing, knows that the things that are required to go back to the House are insignificant and the House has already told us, ‘No problem.' So we don't want to change that."

The drama playing on the Senate floor eventually became a battle of wills between Republicans and Democrats, with each side trying to outlast the other.

Reid finally adjourned the marathon session at about 2:45 a.m. Thursday after striking a deal with McConnell to reconvene later in the morning -- news that was greeted with audible sighs of relief from tired senators.

By the time senators filtered into the chamber Thursday afternoon, the final vote felt almost anticlimactic to Democrats who had expended so much energy to get to that point.

Not only had the comprehensive bill already passed the House with fanfare Sunday night, the fixes package still needed to go back to the House, robbing Senate Democrats of their moment to close the book on health care.

Lisa Lerer, Manu Raju and Carol E. Lee in Iowa City, Iowa, contributed to this story.