Easy. Blacks were not indentured servants. They were SLAVES.
You need to understand the difference.
Indentured servants had a time to serve to pay back the cost of their travel on ships to America. The children of indentured servants were not slaves nor even indentured servants. Indentured servants were free to marry, and their wives/husbands could not be sold to another owner.
Indentured servants were not ever ENSLAVED, and if they chose to leave before their time was up, they could not be easily identified by the color of their skin. Indentured servants (always white) could easily hide themselves among other white people.
Indentured servants learned the trades of their bosses. When they completed their service period, they could go and work that very same trade, and no one would be the wiser about their indentured service time.
Indentured servants ALWAYS KNEW that a time would come when they would be free. Their term was set before they even crossed the Atlantic.
Black slaves (all from Africa) were CHATTEL. The laws applying to them were the same that governed animals that the plantation owner would purchase. The owner could KILL them and never be punished, because it was considered by law the same as killing a cow.
Slaves had zero rights by law, period. Indentured servants had the same rights as other white people, other than the services purchased by the people who paid their passage across the ocean.
THE TWO ARE RADICALLY DIFFERENT.
This is the kind of thing you would know if you had learned accurate HISTORY.