Last week, in a remarkable act of bipartisan statesmanship, Senator Patrick Leahy and Senator Mike Lee joined together to guide the USA Freedom Act (a trimmed down version of the so-called Patriot Act) to passage over the objection of Senate Majority Leader Mitch McConnell.  This strange bedfellows pairing continued last night with the unanimous passage of a Senate Resolution celebrating the ratification of the 13th, 14th, and 15th Amendments, which collectively constitute our nation’s Second Founding.

For too long, the story of this transformational moment in American constitutional history has been overshadowed by what came before.

The 150th anniversaries of the Civil War were rightly greeted by an avalanche of commemorative coverage and analysis. Even 150 years later, it’s clear that the wounds of the Civil War are not completely healed, nor the questions of its turbulent aftermath wholly answered.  But despite these historical and political rifts, there is one thing that can and should unite all Americans, as it has united Senators Leahy and Lee and a unanimous Senate: the wisdom and importance of the constitutional changes wrought by the Civil War and Reconstruction. These anniversaries also deserve coverage and analysis during their sesquicentennial years.

In what scholars call our nation’s “Second Founding,” leaders like John Bingham, Thaddeus Stevens, and Charles Sumner fought for and secured the passage of a series of transformational Amendments: the Thirteenth, Fourteenth, and Fifteenth Amendments to the U.S. Constitution.  While our nation continues to divide over many questions, the enduring principles enshrined in these Amendments remind us of what unites us as Americans.

First among these Amendments is the triumph that was the passage of the Thirteenth Amendment, which transformed our nation’s charter from an aggressively pro-slavery document to one that explicitly prohibits that pernicious institution.  In light of its unquestioned acceptance today, it’s easy to forget that President Lincoln spent the last months of his life waging an aggressive campaign for the Amendment’s passage, including his decision to take the extraordinary step of signing the Amendment before sending it to the States for ratification.

While the Thirteenth Amendment stands as a monument to a vital, necessary, and (today) uncontroversial constitutional change, the Fourteenth Amendment remains the focal point of serious constitutional debate—at street corners, at our kitchen tables, and in courtrooms throughout the nation.  Indeed, it is the critical provision at issue in the Supreme Court’s historic consideration of marriage equality, a decision we’re awaiting in a matter of weeks.  It’s little wonder why.  This Amendment contains some of the most soaring (and important) language in our Constitution, providing birthright citizenship to anyone born on American soil, protecting fundamental rights from state abuses, and enshrining Jefferson’s famous call for equality into our nation’s charter.  Americans may disagree, including the Resolution’s cosponsors, over how to apply these critical protections to particular issues, but no one denies their importance to our nation’s unifying creed.

Finally, this period of constitutional transformation ended in 1870, with the ratification of the Fifteenth Amendment, which banned racial discrimination in voting.  While we continued to debate how to apply this protection to hot-button topics like state voter ID laws, no one thinks that access to the ballot box should be determined by the color of one’s skin.

Taken together, these transformational Amendments set the stage for remaking our country into the “more perfect Union” originally promised by the Constitution in 1787.  They wrote into our Constitution the “new birth of freedom” that Lincoln spoke of at Gettysburg.  Nevertheless, in our collective reverence for George Washington, James Madison, and our other Founding Fathers, these Second Founding Amendments—and the profound changes that they enshrined in our nation’s charter—are all too often overlooked and underserved.

As these Amendments turn 150, they deserve a celebration that’s worthy of their place at the center of our nation’s constitutional story.   And the names John Bingham, Thaddeus Stevens, and Charles Sumner should be as familiar to every American as James Madison, Alexander Hamilton, and Benjamin Franklin. That’s why Constitutional Accountability Center, the National Constitution Center, along with Second Founding Committee Honorary Chair Justice Sandra Day O’Connor and a growing list of partner organizations, are spearheading a celebration of the 150th anniversary of this Second Founding. The resolution championed by Senators Leahy and Lee is an important beginning to a larger nationwide celebration. As a nation, we have spent the last four years learning about and reflecting on what divided us—doesn’t the aftermath of that war deserve equal reflection and celebration of what can and should unite us as we continue to strive towards building a “more perfect Union?”