Pelosi was leading a delegation including members of the Congressional Black Caucus to the West African country, four centuries after the first slave ship arrived in Jamestown, Virginia from the continent.
The legislators visited the ‘Door of No Return’ at a slave fort on the coast from where people were dispatched in chains to the New World.
“At the Elmina Castle we saw the dungeons where thousands were grotesquely tortured, and at the Cape Coast Castle we stood before the ‘Door of No Return,’ where countless millions caught their last glimpse of Africa before they were shipped to a life of enslavement,” she told Ghanaian MPs.
“These profound places are sobering testament to humanity’s capacity for grave evil and also a helpful reminder of the capacity for great resilience, renewal and strength of the people.”
The visit comes amid uproar back home over a string of verbal attacks by President Donald Trump on African-Americans that Democrats have labelled racist.
Trump was heckled by a protester in Jamestown on Tuesday during a speech to mark 400 years since the founding of the first local legislature by English colonists. In it, he denounced the “horrors” of slavery.
Ghana has designated 2019 the “Year of Return” both to commemorate the Africans forced into slavery and to encourage their descendants in the US to “come home”.
The country is seen as a haven of stability in an often turbulent region. Pelosi praised its role in maintaining peace and providing an example of democracy.