Why did the Europeans go to the trouble of importing African slaves instead of using, for example, European indentured servants or Indian slaves?

What were the main social, political, and economic impacts of the slave trade on Europe, Africa, and the Americas? Why did the Europeans go to the trouble of importing African slaves instead of using, for example, European indentured servants or Indian slaves?

"Get 15% discount on your first 3 orders with us"
Use the following coupon
FIRST15

Order Now