The north's naval superiority was most important in the u. s. civil war because a) it kept britain from reaching the south with troop reinforcements. b) the most important battles were fought in along the atlantic coast. c) the south suffered heavy defeats in all of the naval battles of the war. d) it allowed the north to blockade the south and shut off most of its trade.

The correct option is D

Thanks to the northern naval power, this could inflict an ever stricter naval blockade of the Confederate ports, the Union gathered the resources and manpower to attack the Confederation from all directions, leading to the fall of Atlanta by William T. Sherman and his march to the sea.

the constitution gives congress the power to regulate commerce "among" the several states.