The president and first lady Michelle Obama were observed gazing at the Atlantic Ocean from the Door of No Return, the view seen by slaves as they were loaded onto ships. The first family also toured a former slave house that now stands as a museum.
The first family arrived on the island via a small six-boat flotilla, traveling with Senegalese President Macky Sall.
Speaking with reporters aboard Air Force One on Wednesday, press secretary Jay Carney said the visit to the island would be a "powerful" symbol.
"I'm sure particularly so, given that he is African American," Carney said.
Thursday was the first full day of the president's eight-day trip through Africa, which in addition to Senegal will feature stops in South Africa and Tanzania.