In the period before the Civil War, the principle of popular sovereignty meant that whether or not a territory allowed slavery would be left up to A) territorial legislatures. B) the United States Senate. C) the United States Supreme Court. D) the President most recently elected.

The correct answer is A. In the period before the Civil War, the principle of popular sovereignty meant that whether or not a territory allowed slavery would be left up to territorial legislatures.

Explanation:

The principle of popular sovereignty implied that, since the Compromise of 1850, the decision of whether or not to accept slavery in their territories was available to the states. Each state, in particular through its respective legislatures, could vote on the issue of slavery, so that it was popular sovereignty, that is, the will of the people through their representatives that would determine the issue.

A) territorial legislatures. If your state allowed slavery or not was up to the state itself. It was when Abraham Lincoln came in and said that he would ban slavery all over the U. S. that things really went south. But, before the civil war it was all up to the states (aka territorial legislatures)