My parent were born in Nigeria and moved too the U.S. 20 years and I was born here. Just curios if my ancestors were slaves just like the Black Americans with slave blood?
No, a large portion of American (North and South) black people are. The overwhelming majority were not, in fact the slaves sold to Europeans were sold by other black people in Africa.
If your parents are from Nigeria there are more chances that they may have been the slaves of other black Nigerians than slaves of white people since they were in Nigeria until 20 years ago.
Most black people on earth weren't slaves. Most black people in the Middle East, North Africa, and the Americas more often than not have ancestors who were enslaved by European whites or Arabs, Turks, and possibly Persians.