The term kennedy chose to describe his sealing off of cuba to prevent soviet shipments of weapons or supplies was

interdiction
quarantine
isolation
blockade

Quarantine.

Explanation:

Mr. President John F. Kennedy in his speech october 22, 1962 announced quarantine against cuba island.

In this  speech Mr. President said  textually: "I have directed the the following initial steps be taken immediately".

First: To halt this offensive build up, a strict quarantine on all offensive military equipment under shipment to cuba is being initiated.  

you can't, but you can edit them

b.

jim crow laws were enacted in northern states.