President Bush on Thursday signed legislation extending for 25 years the Voting Rights Act, the historic 1965 law which opened polls to millions of black Americans by outlawing racist voting practices in the South. "Congress has reaffirmed its belief that all men are created equal," he declared.

Bush signed the bill amid fanfare and before a South Lawn audience that included members of Congress, civil rights leaders and family members of civil rights leaders of the recent past. It was one of a series of high-profile ceremonies the president is holding to sign popular bills into law.

The Republican controlled Congress, eager to improve its standing with minorities ahead of the November elections, pushed the bill through even though key provisions were not set to expire until next year.

"The right of ordinary men and women to determine their own political future lies at the heart of the American experiment," Bush said. He said the Voting Rights Act proposed and signed by then-President Lyndon Johnson in 1965 "broke the segregationist lock on the voting box."

"My administration will vigorously enforce the provisions of this law and we will defend it in court," Bush said.

The legislation bears the names of three women who were active in the civil rights movement: Fannie Lou Hamer, Rosa Parks and Coretta Scott King. Bush said he was signing the bill "in honor of their memory and their contribution to the cause of freedom."

Hamer, a Mississippi sharecropper, was beaten and jailed in 1962 for trying to register to vote. She co-founded the Mississippi Freedom Democratic Party and gave a fiery speech at the 1964 Democratic National Convention. In 1955, Parks refused to give up her bus seat to a white man in Montgomery, Ala., sparking a mass boycott by thousands, mainly black women domestic workers who had long filled the buses' back seats.

King was a prominent civil rights activist and the widow of slain civil rights leader Martin Luther King Jr.

Later Thursday, Bush is to sign another bill sure to resonate with voters in this congressional election year: legislation establishing a national Internet database designed to let law enforcement and communities know where convicted sex offenders live and work.

By contrast, Bush chose to exercise the first veto of his 5 1/2 years as president in privacy last week, with no audience, no cameras, no reporters. The bill he vetoed would have expanded federally funded research of embryonic stem cells.

White House officials said an open ceremony to veto a bill seemed inappropriate, although other presidents have done just that. Forty minutes after the Oval Office veto, Bush gave a major address on the issue in the East Room, open to the press and surrounded by families who have "adopted" leftover frozen embryos and used them to bear children.

In May, Bush took to the South Lawn to sign into law a bill that extended $70 billion in previously passed tax cuts. That package was also seen by Republicans as an opportunity to boost the popularity of the president and the Republican-controlled Congress

Presidential bill-signings usually occur in an office building next to the White House, not on the South Lawn, and on Wednesday workers scurried to get things ready for the Voting Rights Act signing, setting up water stations and a large stage for Bush and the bill's primary supporters.

The list of some of the 600 expected guests reads like a who's-who of prominent black leaders and civil rights veterans, including the Revs. Al Sharpton and Jesse Jackson; friends and relatives of the Kings, Ms. Parks and Dorothy Height, the longtime chairwoman of the National Council of Negro Women.

Senate Minority Leader Harry Reid and House Minority Leader Nancy Pelosi have used the occasion of the Voting Rights Act extension to criticize Bush's administration for politicizing civil rights policy and weakening enforcement of the law's provisions.

The bill passed the Senate by a vote of 98-0 and the House 390-33. The overwhelming majorities belied the difficulties getting to that point.

Some Southern lawmakers rebelled against renewing a law that requires their states to continue to win Justice Department approval before changing any voting rules — punishment, they said, for racist practices that were overcome long ago.