Eyewitnesses often have different accounts of events, so historians must

Evaluate each account to discover the truth is the correct answer. As there is a possibility of different events recorded by different eyewitnesses but who to believe is the question.

So the historians must evaluate and analyse all the records in such a manner that the eyewitness's account is matched with the other evidences. There should be careful evaluation of all the records to avoid errors and wrong interpretation of the given facts.

d. it adversely affected american productivity

answer: secession

secession, as it applies to the outbreak of the american civil war, comprises the series of events that began on december 20, 1860, and extended through june 8 of the next year when eleven states in the lower and upper south severed their ties with the union. the first seven seceding states of the lower south set up a provisional government at montgomery, alabama. after hostilities began at fort sumter in charleston harbor on april 12, 1861, the border states of virginia, arkansas, tennessee, and north carolina joined the new government, which then moved its capital to richmond, virginia. the union was thus divided approximately on geographic lines. twenty-one northern and border states retained the style and title of the united states, while the eleven slave states adopted the nomenclature of the confederate states of america.

explanation: