Under the colonial system an indentured servants work was

...typically for seven years
...to pay off the servant's debt
...bought and sold
...called temporary slavery

For seven years and basically its temporary slavery

It developed as a reaction to the impact of european colonialism in africa on peoples of african descent. in the  mid-20th century, activists in africa adopted pan-africanism as a rallying cry for independence from colonial rule. some african pan-africanists sought to unite the continent as one independenthope it was useful