What was the theory behind the Nullification crises of 1832?

it was driven by South Carolina politician John C. Calhoun, who opposed the federal imposition of the tariffs of 1828 and 1832 and argued that the U.S. Constitution gave states the right to block the enforcement of a federal law.

Explanation:

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place