Over 1,700 people who served in the US Congress owned human beings as property during their lifetimes, an investigation published on Monday determined.

In all, 1,715 cases of lawmakers who owned people as slaves were found from the 18th through the 20th centuries, the Washington Post newspaper's analysis determined. The study examined censuses and other historical records to compile its findings.

The lawmakers who owned slaves were determined to have represented 37 different states, including states in the South, every state in New England, as well as states in the Midwest and the West.

They spanned a wide swathe of the American political establishment, and represented more than 60 parties, including the Republican and Democratic parties, as well as lesser-known parties, including the Federalists, Whigs, Unionists, Populists, Progressives, Prohibitionists, the Post found.

Still, the Democratic party had the highest number of lawmakers who, at one point in their lives, owned slaves. The newspaper found 606 such cases. There were some 481 congressional Republicans who were identified as slaveowners.

Democratic Sen. Corey Booker, who is just the fourth Black person elected to serve in the US Senate, said in an interview with the Post, "There’s very little acknowledgment of the degree that slavery, that wretched institution, shaped the Capitol."

“All around you, the very Capitol itself, was shaped by this legacy that we don’t fully know or don’t fully acknowledge," he said.

Turning to the White House, the analysis determined 12 of the first 18 US presidents owned people as slaves, including eight who were slaveowners during their presidency.

The Post compiled its findings, which also determined 3,166 congressmen did not own slaves, into a database. There are some 677 congressmen for whom investigations are still outstanding, and the Post said it would be providing updating its database "as more information comes to light." (Anadolu Agency: Excluding headline)