It was important for the Roman army to be able to move soldiers and all their baggage around the country. They built roads as straight as possible, in order to travel as quickly as they could. Winding roads took longer to get to the place you wanted to go and bandits and robbers could be hiding around bends.
I would say 30,000 cause all the next developments were from the 1860's forward and that is when huge growth happened, after 1860.
Answer: The slave trade brought about a negative impact on African societies and led to the long-term impoverishment of West Africa.
Explanation: Brainllest pls