The words “we apologize for slavery” never have made their way into a formal resolution by U.S. lawmakers to be signed by a sitting president. Those words seemed no closer to making it to President Barack Obama’s desk for signature as he and other leaders paid tribute Wednesday to Americans who, a century and a half ago, helped bring about an end to slavery.

“The scars of our original sin are still with us today,” Obama said Wednesday as lawmakers marked the 150th anniversary of the abolition of U.S. slavery. “In America, we can create the change that we seek. All it requires is that our generation be willing to do what those that came before us have done.”

But the speeches given by Obama and congressional leaders during the ceremony marking the passage of the 13th Amendment made no mention of America's long debate over reparations as a way to atone for 245 years of enslaving black Americans. Not even the first black commander in chief, in the final stretch of his presidency, has formally apologized for the nation’s generations-long slave trade, a gesture that could clear the way for some form of compensation to slave descendants, proponents have said. While Congress has worked for years on the language of a formal apology and reparations, opponents and critics have said the idea would create racial rifts over the cost and would be nearly worthless without targeted actions that address slavery’s lasting legacy of socioeconomic inequality for blacks.