What was the primary result of road and turn pike development in 1840?

The primary result of road and turnpike development in 1840 was the increase of migration from East to West.

Along with the evolution of the railroads, these developments were key for America's plans of Westward Expansion in the first half of the 19th century. Under the Manifest Destiny, which consisted on the expansion of dominion and capitalism across North America, the US acquired western territories through treaties.

the answer is a. laws were enacted in the aftermath of the plot to make it harder to free slaves,increasing sectionalism