The House is officially acknowledging the use of African-American slaves in the construction of the U.S. Capitol.
It's ordering officials to place a marker inside the new Capitol Visitor Center using some of the original stone excavated by those slaves for the historic building.
The vote was 399-1, with Iowa Republican Steve King the lone dissenter. The Senate is considering a similar measure.
Historians have found that slaves worked 12-hour days, six days a week on the construction of the Capitol. The federal government rented the slaves from local slave owners at a rate of $5 per person per month. The slaves were not paid.