Answer: B. were not completely unified
The answer would be Agriculture
I know this because I have had a test with same question and it was correct
Hope it helps
Answer:
26 years
Explanation:
The National Road (also known as the Cumberland Road) was the federal government's first significant improved highway in the United States. The 620-mile (1,000-kilometer) road, built between 1811 and 1837, connected the Potomac and Ohio Rivers and served as a major transportation route for thousands of migrants heading west.
