WASHINGTON - President Barack Obama applauded his predecessor Lyndon Johnson for a civil rights legacy that eventually led to the election of the first U.S. black president nearly half a century later. Obama gave the keynote address at a ceremony Thursday marking the 50th anniversary of the signing of the U.S. Civil Rights Act. Former U.S. presidents George W. Bush, Bill Clinton and Jimmy Carter, civil rights leaders and other dignitaries also attended the three-day Civil Rights Summit in Austin, Texas.
The president reminded the audience at the Lyndon Baines Johnson Presidential Library of the significance of the 1964 Civil Rights Act. The law, was soon was followed by the Voting Rights Act and other laws that now are part of U.S. civil society. Obama said those important measures opened new doors of opportunity for many Americans.
"Not just blacks and whites but also women, and Latinos and Asians and native Americans," he noted. "And gay Americans. And Americans with a disability. They swung open for you and they swung open for me."

The president praised Lyndon Johnson for his courage to fight for a cause that many officials had told him was lost.
"And one particularly bold aide said he did not believe a president should spend his time and power on lost causes, however worthy they might be, to which, it is said, President Johnson replied: 'Well, what the hell's the presidency for? What the hell's the presidency for if not to fight for causes you believe in?'" Obama told the audience.
The president also said that the fight started by President Johnson is not over yet.
"As was true 50 years ago, there are those who dismiss the Great Society as a failed experiment and an encroachment on liberty, who argue the government has become the true source of all that ails us, and that poverty is due to the moral failings of those who suffer from it," said Obama.
President Obama insisted that the government has a role in making sure all Americans enjoy equal access to education, jobs, health care and other basic rights.
Civil Rights Movement veteran John Lewis, now a congressman from Georgia, praised Obama's understanding that there is much more to be done in that area. 
"That is why, as president, he has set his shoulders to the plow to bring about meaningful change in America by ending two wars and passing comprehensive health care reform... Thank you, Mr. President," said Lewis.
Obama ended his speech on an optimistic note, saying America is a story of progress, despite challenges along the way.