With Speaker Nancy Pelosi and Congressman George Miller standing behind him, President Barack Obama signed the bill and then hugged the woman whose name is on the new law.
"It is fitting that the very first bill that I sign, the Lilly Ledbetter Fair Pay Restoration Act, that it is upholding one of this nations' founding principles -- that we are all created equal," said President Obama.
Before Thursday you could only file a discrimination suit within six months of first experiencing a pay gap. The new law allows suits to be filed years later, as long as the pay discrimination continues. Opponents like Southern California Congressman Howard McKeon say it'll lead to a flood of lawsuits.
"Trial lawyers, you can be sure, are salivating at this very prospect," said Rep. Howard McKeon (R) of Palmdale.
But Boalt Hall law professor and practicing union attorney David Rosenfeld says there is another statute of limitations.
"I can only go back two years the law is very clear that if I file a claim today, I can go back two years and collect back pay only for those two years," said Professor David Rosenfeld, from Boalt Hall Law School.
Rosenfeld points out that is not a huge incentive for trial lawyers. The difference of $3 an hour on the job would result in a maximum claim of around $12,000.
And the president of San Francisco's Equal Justice Society says the lawsuits that do result from this new law are good thing.
"So this is just a way to bring justice to the American worker," said Eva Paterson, from Equal Justice Society.
Lilly Ledbetter will not see any money from her lawsuit because of this new law. Her former employer Goodyear Tire and Rubber issued a statement saying the Ledbetter law will erode the prompt reporting of discrimination.
