Sen. Cory Booker (D-N.J.) testifies about reparation for the descendants of slaves during a hearing before the House Judiciary Subcommittee on the Constitution, Civil Rights and Civil Liberties, June 19.

The 400th anniversary of slavery in the United States coincides with a Democratic presidential primary in which reparations for slavery have played a surprisingly prominent role. Marianne Williamson proposed providing up to $500 billion in repayment to black Americans, while Sen. Cory Booker (D-N.J.) has reinterpreted reparations through “baby bonds”and a proposed measure to study the effects of slavery.

Though reparations may not be broadly popular, their economic value is undeniable. Closing the racial wealth gap stands to stimulate an entire nation, adding an estimated $1.5 trillion to the U.S. economy.

To do that, though, we need to reckon not just with the value of the unpaid labor performed by generations of slaves but also with the impact of land thefts that cost freed slaves the most important asset they acquired in the years following emancipation. It may be challenging to calculate what a cotton-picker’s wages might have been in the absence of a free labor economy and how those wages might have grown into wealth over generations. But we have always assessed the value of land in blunt terms. Reparations for land thefts wouldn’t just put a stark number on what was stolen from black Americans, it would force us to reckon with the idea that the Emancipation Proclamation does not represent a clear dividing line between one era of American history and the next.

The consequences of such thefts ripple through generations. According to a2015 report, land in Arkansas today is worth roughly $6,739 per acre, valuing the approximately 150 acres my family lost at more than $1 million. The loss of that land dramatically shifted our family’s financial trajectory across generations. Even if Luisa and her descendants had not been able to farm it successfully, if the family had been able to hold on to the land and sell it at a fair price, that asset could have laid the foundation for a very different future.

We are not alone. Though the issue of land loss has recently returned to public attention, this part of our history has been well reported and understood for years. In 2001, the Associated Press published a thorough investigation into the heinous loss of land experienced by black families like mine. Interviews with 406 victims whose families lost 24,000 acres of land worth tens of millions of dollars unearthed harrowing stories of pilfered properties. Some thefts were accomplished by legal subterfuge, others through lynching. Lost land continues to be the driving factor of America’s billion-dollar debt to black people. The result of that debt means that the average black family would need 228 years to amass the wealth of an average white family.

So to the presidential candidates who have expressed support for reparationsbut failed to share concrete proposals, what is your strategy to repay black slave descendants ? Your future constituents deserve to know. And when the complex but solvable question of “how” inevitably deters your action, think first of families such as mine — families whose ancestors lost millions a short century ago, and have been distanced from the American Dream as a result.

Read more:

Ken Woodley: Virginia is proof that reparations for slavery can work

Jonathan Capehart: No reparations check of any amount could substitute for an apology

Charles Lane: Would reparations for slavery be constitutional?

Richard Cohen: A tale of two Washingtons, one a slave, the other a master

Clarence J. Fluker, C. Kinder, Jesse Moore and Khalilah M. Harris: We are African Americans, we are patriots, and we refuse to sit idly by