Did Amerigo Vespucci Have Slaves?
Your question is – did Amerigo Vespucci have slaves?
My answer in one word is ‘Yes’.
Of course, he had so many slaves. Even, he bought and sold them for making profits.
During that period of time, slavery was a very normal thing for Europeans.
Even, Vespucci had been in the slavery business in the African continent (Black slaves) for many years.

Prove we can see in his will written in 1511 (before a year of his death).
I don’t know whether they were black or other slaves, but here he willed that he would leave most of his properties and five household slaves to his wife.
His wife’s name was Maria Cerezo. In his will, he mentioned her as the daughter of Gonzalo Fernández de Córdoba.
Due to having no children, he willed everything to his wife’s name.
On the other hand, when he traveled to the new world (future America), he captured so many natives as slaves to sell.
For example, during his voyage from 1499 to 1500, he captured 232 natives on the Bahamas island to take them to Spain for selling.
However, it did not make him so much profit.
Hope this answer will help you a bit in clearing your doubt.

Was Amerigo Vespucci A Tyrant Towards Slaves?
It is controversial, everyone had different viewpoints on this issue.
But from my viewpoint, slavery itself was a tyranny. Everyone who was involved in it was a tyrant.
That is why Amerigo Vespucci also can’t run away from it.
But again, during that period of time, slavery was a very normal thing for the white European race.
So, from this point of view, it will not be fair to say Vespucci was a tyrant because he was doing what was going on in his society.
At least, he was a far better person than Christopher Columbus.
Vespucci did not do the atrocities that Columbus had done on native people while exploring the new continent.
[Did You Know? Christopher Columbus Was One of The Worst Guys In American History. He Executed Many Atrocities On Native American People. Follow This Article To Learn About His Atrocities: Link]