What role did the geography of the sahel play in the rise of the medieval african kingdoms?

it provided access to the large ports on the atlantic.

the lack of fresh water made rulers here more warlike.

it provided a place for trade between the north and the south.

the desert was difficult for outsiders to invade.

both are true, the congress does have the power to create banks, even if this power is not specifically described in the constitution, since there is nothing restricting it and there is power given to the congress to make "all laws which shall be necessary and proper". maryland was not allowed to tax a branch of the national bank operating there, and the supreme court decided that no state could. both of these topics were discussed in a decision of the mcculloch v. maryland case in 1819.