What challenges does Lincoln present to the audience?

First, he addresses the American public when he says, “My countrymen, one and all, think calmly and well upon this whole subject.”

He also speaks to the people who are on the fence regarding secession. He says, “That there are persons in one section or another who seek to destroy the Union at all events and are glad of any pretext to do it I will neither affirm nor deny; but if there be such, I need address no word to them. To those, however, who really love the Union may I not speak?”

He addresses Southerners who are threatening to secede as "fellow-countrymen": "In your hands, my dissatisfied fellow-countrymen, and not in mine, is the momentous issue of civil war.”

He could also be talking to other audiences, such as the international community amid the growing tension in the United States. Lincoln would want to reassure allies abroad of his authority as the new president.

Explanation:

: b : o   : 0 ; b : - )  

: b: b: b: b: b: b: b: b: b