Knights were indeed lower than vassals and held less prestige in medieval society. It's not true though, that knights didn't have enough prestige in medieval society. Vassals swore to the king or the ruler of a region, whereas knights often swore to vassals, so they still had people under them, but they were not at the top.
The three-fifths compromise provided for counting slaves for representation in Congress and in the electoral college.
-They fear Cuba will inspire others to rise up against US domination.
Castro told the Cuban people that the US was afraid of a Cuban Revolution because it would inspire communism in the US. This explanation gave pride to the Cuban revolutionaries and explained why the US was reacting harshly to the revolution. The US placed trade embargoes on Cuba and even moved toward military protections against the new Cuban communist government.