Did Ulysses S. Grant own slaves?

Ulysses S. Grant led the Union to victory in the Civil War, but he had complicated views on slavery. His father was an abolitionist, but in 1848, Grant married Julia Dent, whose family owned thirty slaves. Ulysses and Julia lived on the Dent family farm, and Grant was known to have worked alongside the slaves in the fields.
In 1858, Grant gained possession of his own slave, William Jones. It's not clear whether Grant purchased or was given Jones, but he set him free a year later. This was the only slave that Grant ever owned himself. Grant was always quiet about his personal views regarding slavery, but he knew that the country needed to exist as one: if slavery was dividing the country, then it would have to cease to exist.