How did the US coastline provide an advantage for the South during the Civil War?

Southerners enjoyed the initial advantage of morale: The South was fighting to maintain its way of life, whereas the North was fighting to maintain a union. Slavery did not become a moral cause of the Union effort until Lincoln announced the Emancipation Proclamation in 1863.

Explanation:

none needed!

It made it difficult for the Union to create blockades.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

the answer is true. i hope this .