So, just how soon will Americans start reaping the benefits of tax cuts in it?
By April 1, according to the president.
"Never before in our history has a tax cut taken effect faster or gone to so many hardworking Americans," Obama said Saturday in his weekly radio and Internet address.
He said the Treasury Department has begun directing employers to reduce the amount of taxes withheld from people's paychecks in accordance with the new law, and that in six weeks, a typical family will start taking home at least $65 more every month.
Obama says his signature "Making Work Pay" tax break will affect 95 percent of working families.
The $400 credit for individuals is to be doled out through the rest of the year. Couples are slated to get up to $800. Most workers are to see about a $13 per week increase in their take-home pay. In 2010, the credit would be about $7.70 a week, if it is spread over the entire year.
People who do not earn enough money to owe income taxes are eligible for the credit, an attempt to offset the payroll taxes they pay.
Obama's expensive and ambitious package of federal spending and tax cuts is designed to revive the economy and save or create 3.5 million or more jobs. It will inject a sudden boost of cash into transportation, education, energy and health care, while aiming to help recession victims through tax cuts, extended unemployment benefits and short-term health insurance assistance. It also will add to a rapidly growing national debt.
The president signed the measure into law Tuesday.
In his weekly address, Obama said he was grateful to Congress, governors, mayors and everyday people who supported the measure.
Still, he added: "It is only a first step on the road to economic recovery. And we cannot fail to complete the journey." He said the country also must stem foreclosures, repair the banking system, get credit flowing again and revamp financial industry regulations.
And, even as he promoted the record-breaking spending plan, he called for doing what's necessary to control "exploding" deficits as the economy begins to improve.
Obama is holding a bipartisan "fiscal responsibility summit" at the White House on Monday to talk about ways to control the trillion-dollar budget deficit. The next day, he is to address a joint session of Congress, a speech expected to focus heavily on the economy. On Thursday, Obama will send a budget request to Congress "that's sober in its assessments, honest in its accounting, and lays out in detail my strategy for investing in what we need, cutting what we don't and restoring fiscal discipline."
Republicans are certain to hold him to that.
In the GOP's weekly address, Rep. Dave Camp of Michigan, the top Republican on the House Ways and Means Committee, said his party wants to work with Obama to solve the country's economic problems "in a responsible way that does not burden our children and grandchildren with a mountain of debt."
"We can't borrow and spend our way back to prosperity," Camp said. "If he is serious about dealing with the tough issues and getting spending under control, his budget will show it."