President Lyndon Johnson believed that Americans can build a fairer, more equal and freer society than the ones they inherited, President Barack Obama said April 10.

"He believed we make our own destiny," Obama said. "And in part because of him, we must believe it as well."

The president delivered a half-hour keynote address on Johnson's contributions to civil rights and the country's responsibility to continue his work at the Civil Rights Summit at the Lyndon B. Johnson Presidential Library in Austin.

He was joined by First Lady Michelle Obama. Singer Mavis Staples sang "We Shall Overcome" before U.S. Rep. John Lewis introduced the president.

In his address, Obama said Johnson's "Great Society" domestic policies—including the Civil Rights Act of 1964, the Voting Rights Act of 1965, the Immigration and Nationality Act of 1965 and the Medicare Bill of 1965—were inspired by the Johnson's own experiences with poverty as a child and later as a teacher.

"Deprivation and discrimination -- these were not abstractions to Lyndon Baines Johnson," Obama said. "He knew that poverty and injustice are as inseparable as opportunity and justice are joined. So that was in him from an early age."

Obama praised the former president's mastery of politics and the legislative process. "He grasped like few others the power of government to bring about change," he said.

He also praised Johnson's desire to fight for what others deemed risky political moves.

"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," Obama said. "To which, it is said, President Johnson replied, 'Well, what the hell's the presidency for?'"

Fifty years later, the country remains locked "in the same great debate about equality and opportunity and the role of government in ensuring each," Obama said.

"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 that 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," he said.

Obama said he rejected those ideas because he and his family have lived out the promise of Johnson's efforts.

"Because I and millions of my generation were in a position to take the baton that he handed to us," he said. "And that means we've got a debt to pay. That means we can't afford to be cynical. Half a century later, the laws LBJ passed are now as fundamental to our conception of ourselves and our democracy as the Constitution and the Bill of Rights. They are foundational; an essential piece of the American character."

He said that Civil Rights Act's anniversary teaches young people everywhere "that with enough effort, enough empathy, enough perseverance and enough courage, people who love their country can change it."