There is a certain sense in the minds of millions in the aftermath of the U.S. presidential election, that we have reached the promised land.

The imagery and oratory of the Rev. Dr. Martin Luther King, Jr. is invoked, to suggest that his Dream, as articulated in his epic “I Have a Dream” speech, has been realized.

There is a deep sense that freedom is here, as we all live in a “post-racial America.”

Or do we?

To be sure, we are all on the brink of history, for this has never happened before.

But there was a time, quite a while ago, when similar feelings swept the nation, and especially Black hearts, that a new day was breaking, and the old ways had fallen away, when freedom was as real as rain.

I speak of the Reconstruction era, when the nation formally extended civil rights to millions of Black men (not to women, notably) and scores of Black people took office in state and federal legislatures, beginning a wave of progressive legislation to better the abominable living conditions of millions, Black and white alike.

But Reconstruction was short-lived, due to the assassination of Abraham Lincoln, the betrayal of Black freedmen by the federal government, and the campaign of white terrorists against Black people and Republicans, which converged to reassert white supremacy.

The Supreme Court also played a pivotal role in the Slaughterhouse Cases (1873), which, despite the clear language of the 13th, 14th, and 15th Amendments, supported states rights over federal constitutional rights, and thus signaled to the South that its denial of rights and segregation of Blacks wouldn’t offend their reading of the Constitution.

The hopes, dreams and freedoms of millions were dashed for more than a century, so that the lie of white supremacy could prevail.

At the end of the Civil War, when slavery was formally abolished, Black people were so joyous that many changed their names to reflect this new-found freedom to define themselves. They organized their own churches. They opened schools and businesses. They ran for and won local and national offices. They sat on juries. And they married in droves.

Within a generation, all of these freedoms were washed away, by law, custom and a vicious reign of racist terrorism.

What this history revealed is freedom can be ephemeral.

It matters not what is written in constitutions, nor the rhetoric or promises of politicians. It matters what people fight for.

If history teaches us anything, it is that it matters what social movements struggle for.