When Gen. Robert E. Lee surrendered the Confederate Army of Northern Virginia to Lt.-General Ulysses S. Grant at Appomattox on April 9, 1865, an exchange of their respective seder plans was not high on their list of priorities. As American Jews celebrate our festival of freedom and the sesquicentennial anniversary of that historic day, it is an opportune time to consider the significance of April 1865 in our nation’s history and reflect how that historical pivot continues to shape the landscape of our country.

Although 1776 was the year of our nation’s founding, 1865 was arguably the first time that the ideals embedded in the Declaration of Independence were given the opportunity for full expression. Familiar as we are with Jefferson’s words, “that all men are created equal,” we are also undoubtedly aware of the fact that he, Washington, Madison and Monroe, among other Founding Fathers, were slaveholders.

To be sure, Jefferson’s initial draft of the Declaration did contain a denunciation of slavery, a passage excised at the urging of delegates from South Carolina and Georgia. Nevertheless, whether considering the slaves of his own household, his reflections on Negro inferiority in his “Notes on Virginia,” or his reticence to address the issue of slavery head on, an honest assessment of our nation’s founding must at some point confront the moral paradox built into our “almost-chosen” nation.

As with so many leaders, past and present, Jefferson and his contemporaries kicked the issue of slavery down the road. In Jefferson’s own words, “It is to them I look, to the rising generations, and not to the one now in power for these great reformations.”

The boiling point would come with the Civil War — the shots fired at Fort Sumter in 1861, and not at Lexington in 1775, served as the birth pangs of our nation.

“Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal” — Lincoln’s Gettysburg Address was ostensibly meant to dedicate a cemetery, but what he understood better than anyone was that it was not only to the memory of fallen soldiers to which his dedication was aimed, but to the vision of the Founding Fathers, to “a government of the people, by the people and for the people.”

Even after the Emancipation Proclamation, it would still take nearly 18 months and thousands of American lives before the fighting would come to an end. As Lincoln intoned in his famed second inaugural address, both sides “read the same Bible and pray[ed] to the same God,” constituting a nation divided not just by geography or interpreting the constitution, but by the interpretation of sacred scripture itself.” Just over one month after his call to “finish the work we are in,” just one week after the surrender of General Lee to Grant, on the Sabbath of 1865, Lincoln was assassinated, having seen, but not yet entered, the Promised Land.

The end of the Civil War did not draw our nation’s struggle for freedom to a close. In the words of Fredrick Douglass: “Verily, the work does not end with the abolition of slavery, but only begins.” For the newly emancipated African American community, the coming years would be marked by “ambiguity, tragedy and complexity.”

As for white America – old hatreds, as the saying goes, die hard. It is far from a coincidence that the Ku Klux Klan was founded in the year following the Civil War. Most of all, as Jay Winick explains in “April 1865,” his study on the subject, it would be the world of race relations that would continue to suffer. State after state, restrictive legislation regarding segregation, intermarriage, land ownership, voting rights and countless other forms of racial repression continued to dominate the American landscape. Not unlike our Passover story itself, the generation of the Exodus would not necessarily be the generation able to fully enjoy the taste of freedom.

All of which was undoubtedly not lost on Martin Luther King Jr. as he sat that Passover day of 1963 in the Birmingham jail. In a passage that could have just have easily been written by Moses himself, King wrote: “We know through painful experience that freedom is never voluntarily given by the oppressor; it must be demanded by the oppressed.”

The brilliance of Kings’ rhetoric of civil rights was that he positioned his cause not as something new, but as the logical and necessary fulfillment of Lincoln’s vision. It was no accident that just a few months after Birmingham, in the shadow of the Lincoln memorial, King began his “I have a Dream Speech,” with the words “Five score years ago.”

Be it Brown vs. Board of Education, Rosa Parks or otherwise, the Civil Rights movement leading up to the Civil Rights Act of 1964 that outlawed discrimination based on race, color, religion, sex or national origin was an effort to fulfill the vision expressed, but never realized, by Jefferson. Of course, the Civil Rights Act would not mark the end of the journey, but become just another step along the way. Not unlike Lincoln and altogether like Moses, having reached the mountaintop, King never would enter the Promised Land.

It is Passover 2015, a century and a half after Appomattox and 50 years after Selma. Passover calls on us to reflect not just on the Jewish journey to freedom, but on the struggle of those still seeking to realize the biblical vision of the founding document of the Jewish people, a humanity created in the image of God, granted equal and infinite dignity regardless of race, religion, gender or sexual orientation. One need not look very far to know that we have yet to realize the expressed vision of the Bible or the Declaration of Independence.

The events of Ferguson and beyond make it abundantly clear that insofar as citizens of color are concerned, “we must continue to strive to finish the work we are in.” Though faded, the stain of our nation’s founding, nevertheless, remains. It will only be by way of the sustained activism of our generation and the generations to come that we live to see it cleansed.

On this history filled Passover, let us work to identity the freedoms yet to be won on the landscape of our great nation, and most importantly, recommit ourselves to the work still to be done.

Elliot J. Cosgrove, Ph.D., is rabbi of the Park Avenue Synagogue and host of Righteous Radio on SiriusXM.