On July 2, 1964, President Johnson signed into law the Civil Rights Act. Its enactment, following the longest continuous debate in the history of the U.S. Senate, enshrined into law the basic principle upon which our country was founded – that all people are created equal.

We celebrated the 50th anniversary of the act, which codified the simple principle that we should not be judged based on the color of our skin, or where we choose to worship, or our sex, or the country from which we came. It meant that a person could no longer be turned away from a lunch counter, or forced to use a separate bathroom, or be denied a job simply because they were African-American, or a woman, or from a different country.

But the struggle for the Civil Rights Act was about more than simply ending discrimination. It was about ending economic injustice and fighting for fair and equal access to good jobs and decent wages. It was about fighting for the opportunity to strive for the American Dream, without unjust barriers.

As President Obama said last summer, standing on the steps of the Lincoln Memorial to mark the anniversary of the March on Washington, “For the men and women who gathered 50 years ago were not there in search of some abstract ideal.  They were there seeking jobs as well as justice – not just the absence of oppression, but the presence of economic opportunity.”

The 50th anniversary is a chance to celebrate the remarkable progress made over half a century. But it’s also a reminder that we have unfinished business to address. For many people, and particularly in communities of color, the basic bargain of America – that if you work hard and play by the rules, you can share in the nation’s prosperity – has become a raw deal.

That’s what President Obama’s opportunity agenda is all about – making good on our country’s half of the basic bargain. It’s about making sure everyone has the chance to punch their ticket to the middle class. It’s about providing access to good jobs that can support a family. It’s about helping people acquire the skills to compete for those jobs. It’s about ensuring access to a world class education.

It was a privilege to serve as the assistant attorney general for civil rights, a role that allowed me to enforce the Civil Rights Act and help make its promise a reality. Now, as labor secretary, I am able to continue to work to advance civil rights, helping more people access economic opportunity, and continuing our nation’s journey toward true equal justice for all.