According to some historians which marks the beginning of the US civil war

Battle of Fort Sumter

Explanation:

The Battle of Fort Sumpter marked the beginning of the Civil War.

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

answer: the correct answer is d. a christian revivalist movement in the u.s. during the early 19th century

explanation: the second great awakening was lead by the preachers of baptist and methodist congregations in order to gain support for the protestant religion from the 1790's to 1840's