PLEASE HELP ME I'LL GIVE BEAINLIST!! Which was an obstacle in building the National (Cumberland) Road?

American Indians attacked the crews building the road.
Roads had to be built by hand with picks and shovels.
The Spanish blockaded the Mississippi River.
Workers had to build a bridge over the Grand Canyon.

answer; the importation of slaves from africa,//   is the correct answer.

can you tell me where are the ansawer choices

i'm not sure what you are asking, but it also served as a debtors colony, was ran by the trustees for 20 years until becoming a royal colony, and people had restrictions such as no slaves, and only 50 acres of land per person/ hope this !

- jack watson