Why did the Union want to block the Southern ports?

Thomas jefferson was the president of the united states. first second third fourth

Which answer best describes the u.s. national road? it ran from atlanta to baltimore and followed the railroad. it ran from new york to chicago and was made from wooden planks. it ran from massachusetts to ohio and ran parallel to the canal system. it ran from maryland to illinois and was made using macadam construction.

Classify the most significant contributions of the two major indian empires to world culture