Why is there not many art pieces from Sub Saharan Africa before the 13th century?

How was slavery in mesoamerica, africa, and the arab world similar? many enslaved people were forced to pledge loyalty to their owners. many enslaved people worked in exchange for protection from foreigners. many enslaved people were captured during war. many enslaved people taught and tutored children.

What was herbert hoover and the food administration do in wwi?

How did farm families get things they needed, such as cloth, in the mid-1800's