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Dr. Martin Luther King Jr., one of the architects of America’s struggle for racial justice, would have been 90 years old on Tuesday. This year also marks the 400th anniversary of the arrival of enslaved Africans on the shores of Jamestown, Va., the dawn of the black experience in what would become the United States. These two historic milestones offer us an opportunity to examine King’s political legacy, influence and resonance in our own time.

The modern civil rights struggle represented a Second American Reconstruction, the sequel to the nation’s original post-Civil War attempt to fundamentally remake the nation as a true democracy. These efforts ended in the heartbreak of massive anti-black violence, lynching, imprisonment and land dispossession. By the end of the 19th century, America had indeed been remade, not as a racially integrated democracy but as an apartheid state euphemistically referred to as Jim Crow.

Reconstruction is usually framed as the period from 1865 to 1877 that witnessed the passage of the 13, 14, and 15th Amendments to the Constitution. Those amendments ended slavery, institutionalized birthright citizenship and provided the vote for black men. The subsequent period from 1877 to 1896 featured the systemic disenfranchisement of blacks through organized racial terror and state and local laws that “redeemed” white supremacy in the South. The historian Rayford Logan famously referred to this period as the “nadir” of African American history. In truth, the period of Redemption was part of the Reconstruction era. The hopes that interracial democracy could usher in black citizenship through a literal and figurative reconstruction of American democracy proved premature. But a substantive transformation did, in fact, take place. The Jim Crow system enshrined in law, upheld by the Supreme Court’s 1896 Plessy v. Ferguson decision and guaranteed through the violent subjugation of black bodies — African Americans were murdered by night riders, incarcerated through convict-lease systems and slaughtered in racial pogroms across the country — fundamentally altered the nation-state.

Martin Luther King Jr. served as the major political mobilizer during the Civil Rights Movement’s heroic period. Bookended by the legal integration of public schools in 1954 and the passage of voting rights in 1965, this era represents the first half of the Second Reconstruction. The subsequent Black Power era, the first three years of which King lived to see, ratcheted up the civil rights movement’s push for radical reform by offering a structural or systemic critique of racism, war, poverty, inequality, sexism and violence.

King’s radical legacy continues to be overwhelmed by his iconography at the exact time we need it the most. King is presented to school children and the general American public as an advocate of nonviolence who quietly pushed for racial and political reforms that achieved black citizenship before his untimely assassination. Nothing could be further from the truth. King wielded the specter of nonviolent civil disobedience as both sword and shield in his unrelenting quest for black citizenship. He questioned the fundamental structure of American capitalism, inspired by the racial uprising in the Watts neighborhood of Los Angeles in 1965, and openly wept after witnessing barefoot children in Marks, Miss., accompanied by parents who went without heat and blankets in the winter and food year-round.

The radical King spoke truth to power to sitting American presidents, questioned the fundamental unfairness of capitalism, blasted the Vietnam War, and railed against militarism, racism and materialism. King marched alongside Black Power activist Stokely Carmichael in the withering heat of Mississippi, accused the U.S. Congress of being unapologetically racist, and planned a campaign of massive civil disobedience in Washington, D.C., under the banner of poor people across the racial spectrum.

If this sounds familiar, it should. Contemporary social justice movements, and the forces of racial oppression, white supremacy, economic injustice and violence that have spurred these new struggles, echo aspects of the First and Second Reconstruction. America’s Third Reconstruction is rooted in a historical context that produced the watershed presidential election of Barack Obama. It also produced the Great Recession of 2008 and its continuing impact on communities of color; the fires of Ferguson, Mo., and Baltimore; and American involvement in continuous global warfare. The racial oppression blacks faced in the 1960s has, in many instances, undergone an evolution rather than being eliminated from our body politic.

King’s contemporary legacy can be seen in the Black Lives Matter Movement and its subsequent policy agenda calling for a massive redistribution of wealth and resources toward racial and economic justice. Movements to end mass incarceration, racial segregation in housing and education, unemployment, hunger and violence plaguing urban, rural and suburban ghettoes in America represent the direct results of King’s radical political activism.

White supremacy altered Reconstruction, popularized in the imagery of the Ku Klux Klan and other expressions of organized racial terror. Larger numbers of white Americans participated in black subjugation through both active participation in segregated churches, civic, political and social groups and quiet consent to flourishing anti-black violence. Recently, one aspect of that violence has been memorialized in the the National Memorial for Peace and Justice in Montgomery, Ala., founded by human rights activist Bryan Stevenson.

White racists during the civil rights era organized under the banner of the White Citizens Councils. Comprising some of the leading citizens of the South, the councils gave a respectable face to the political, economic and racial status quo. Their organized efforts at “massive resistance” against the integration of public schools helped resurrect nostalgia for the Confederate flag, funneled public taxes into the creation of all-white private schools, and provided moral authority for violence and the murder of civil rights activists.

America’s Third Reconstruction features some of the same historical cast of characters operating, once again, under a new name. The “Alt-Right,” sometimes lauded by President Trump and his associates, represents the contemporary form of massive resistance against black citizenship and racial integration and the quest to redeem white privilege.

Donald J. Trump’s 2016 presidential election and subsequent administration have provided ballast for multiple forms of white supremacy — civic, political, religious — that have sanctioned the racial and religious scapegoating of blacks, immigrants, Muslims, women and other marginalized groups.

King’s 90th birthday is an extraordinary opportunity to examine how far we have traveled as a nation toward the dream of racial and economic justice for all and the distance that still remains in achieving his notion of a beloved community. Struggles thought to have been won, such as voting rights, continue to be debated in courts and nationally, with the current stalemate resulting in the kind of voter suppression unseen since the days of Jim Crow. New rights arenas have been revealed by LBGTQ, Muslim, non-able-bodied, LatinX and other communities that build upon, while expanding, the fights King led.

The revolutionary King searched for universal social justice for all through the particular movement for black citizenship. He defined black citizenship as not merely the absence of racial injustice but the right to a guaranteed job and income, decent housing, safe and racially integrated communities, health care, food justice and a society where those who felt left out could marshal the “right to protest for right.”

Racial slavery, from its fateful appearance in Colonial Virginia in 1619 to its resoundingly powerful afterlife in our own time, represents America’s Promethean story, a narrative that King proudly claimed as a badge of honor rather than a mark of shame. The black freedom struggle from slavery to Black Lives Matter continues be mistaken by some for a burden when it is better recognized as a tremendous responsibility.

The heroic efforts of the past can infuse present movements with ballast for the difficult days ahead. The beloved community that King envisioned and the promised land of racial justice he glimpsed during his lifetime remain visible on the distant horizon as another country that can be achieved only through a collective understanding of our national history. That history is one that a new generation now bears and will be better able to shoulder by wrestling with the way in which King’s life and holiday represent more than just a celebration of the past but offer a window into a liberated and more humane future for us all.