WASHINGTON (AP) - Some workers who helped build the White House and Capitol, two national landmarks of democracy and freedom, weren't free at all. They were slaves, and a local television station reported Thursday that it has obtained the pay slips to prove it.

Historians have known for years that local property owners loaned slaves to help build the president's residence and the meeting house of Congress, but details of their work have laid in archives and libraries for generations.

On Thursday, WRC-TV, an NBC-owned station in Washington, reported that it had obtained actual pay statements found in Treasury Department papers at the National Archives.

The station reported that the two building projects employed 650 people over eight years, including 400 slaves and more than 50 free Blacks. The slaves earned $5 a month, which was given to slaveowners, who hired them out, the station reported.

Rep. J.C. Watts, R-Okla., says he'll introduce a resolution in Congress later this month to recognize the contribution the slaves made. "It's time the role African Americans played be fully realized and given the honorable recognition that they deserve,'' he said in a statement released Thursday.

By the spring of 1800, work on both the Capitol and the White House was nearing completion. President John Adams moved into the White House and Congress held its first session in the Capitol in November of that year.

"The backbone of the labor force in Maryland and Virginia at this time were Black people, slaves - mostly slaves,'' said William Allen, an historian in the Office of the Architect of the Capitol.

In his history of the District of Columbia, author Keith Melder writes that some of the free Black men and skilled slaves who worked on the Capitol and White House were subsequently laid off.

"Funds had run out,'' he wrote. "The unstable employment situation on federal construction was the cause of much hardship among the workers and their families.''