Definition: This event turned the tide prior to the Civil War. Less than a month after this, South Carolina and other states declared their intent to secede from the United States.

The answer to this question is the following.

Explanation:

Election in the United States of America happened in 1860, in which the 16th president of America, Abraham Lincoln was elected. Lincoln, the republican candidate defeated the candidate of the Southern Democratic Party candidate, John C. Breckenridge and divisions in the country erupted which triggered the expression of interest by the southern states to secede from the Union. This was one of the key contributing factors to the civil war the nation witnessed around April 1861.

answer; the president uses mass media to gain support for policies;