On August 6, 1965, President Lyndon Johnson signed the Voting Rights Act into law, calling it “one of the most monumental laws in the entire history of American freedom.” The ensuing 50 years have proven President Johnson right and vindicated the long struggle of the civil rights activists who fought for its passage. Although voting discrimination still remains all too common, the VRA’s tools to end racial discrimination in voting have nonetheless played a critical role in bringing our nation ever closer to achieving the national ideal of equality under the law.

But as we mark this important anniversary of the VRA’s initial passage, it’s worth remembering that it’s not the VRA’s only anniversary. The VRA has many anniversaries, and that tells us something important about the law itself and the significant congressional power that it reflects.

When the VRA was first passed in 1965, it was intended, as the Supreme Court put it the next year, “to banish the blight of racial discrimination in voting, which has infected the electoral process in parts of our country for nearly a century.” In upholding Congress’s power to enact the law, the Court observed that “Congress felt itself confronted by an insidious and pervasive evil which had been perpetuated in certain parts of our country through unremitting and ingenious defiance of the Constitution,” and it concluded that “the unsuccessful remedies which it had prescribed in the past would have to be replaced by sterner and more elaborate measures in order to satisfy the clear commands of the [Constitution].” The passage of the VRA, with its new remedies to combat racial discrimination in voting, thus reflected a strong national commitment to ensuring that no one should be denied the right to vote on account of race.

Over the past 50 years, Congress has repeatedly renewed that promise, amending and reauthorizing the VRA over and over again. The law was renewed in 1970, 1975, 1982, and, most recently, in 2006.

In reauthorizing the legislation in 2006, Congress acknowledged that “[s]ignificant progress has been made in eliminating first-generation barriers experienced by minority voters,” but concluded that “vestiges of discrimination in voting continue to exist” and “racial and language minorities remain politically vulnerable, warranting the continued protection of the Voting Rights Act of 1965.” Indeed, Congress compiled significant evidence demonstrating the continued need for the law. Following that extensive investigation, Congress voted in favor of the law by huge margins (98-0 in the Senate and 390-33 in the House), and President George W. Bush signed the bill into law, promising to “vigorously enforce [its] provisions.” It is difficult to imagine a more overwhelming show of bipartisan support for a law and the purposes it serves.

Given that overwhelming show of support and the unequivocal demonstration of the continuing need for the law, it is all the more astonishing that the Supreme Court invalidated a key provision of the law in 2013 in Shelby County v. Holder. Writing for a five-Justice majority, Chief Justice John Roberts observed that “‘the Act imposes current burdens and must be justified by current needs’” and rejected essentially out of hand Congress’ unequivocal conclusion that the provision at issue was justified by current needs.

In invalidating the provision, the Chief Justice also gave incredibly short shrift to the Fifteenth Amendment, the constitutional provision that gives Congress the authority to enact the VRA. Indeed, reading the Court’s opinion and its tribute to state sovereignty, one might almost be forgiven for thinking that our nation’s constitutional history ended long before the Fifteenth Amendment was adopted. But, of course, it did not.

And that is why this anniversary of the VRA is also an occasion to remember other anniversaries that are currently or soon to be upon us—the 150th anniversaries of the adoption of the Thirteenth, Fourteenth, and Fifteenth Amendments, adopted in 1865, 1868, and 1870, respectively. With the adoption of these Reconstruction Amendments—often called our nation’s “Second Founding”—our nation recommitted itself to the promise of equality that is central to our national identity.

Among other things, these Amendments abolished slavery, guaranteed that all persons are equal under the law, and provided that no one should be denied the fundamental right to vote based on the color of their skin. And, determined to see these promises realized, the Reconstruction Framers gave the federal government significant power to enforce these guarantees. The VRA has been a critically important (and repeated) exercise of that power.

So as we commemorate the 50th anniversary of the VRA, we should also remember that it is a law with many anniversaries. And each of those anniversaries is an additional reminder of the importance of our nation’s Second Founding and the important power it gave Congress to enact laws, like the VRA, that are necessary to help us realize our national goal of equality under the law.