Final answer:
The excerpt from Wilson's 'War Message to Congress' most appealing to emotions is the statement about the solemnity of leading a peaceful nation into war, evoking fear, sorrow, and patriotism.
Step-by-step explanation:
The excerpt from Woodrow Wilson's 'War Message to Congress' that appeals most to the audience's emotions is: "It is a fearful thing to lead this great peaceful people into war," which Wilson declared to Congress on April 2, 1917. This statement taps into the inherent dread and sorrow associated with plunging a nation of people, who had hoped to remain at peace, into the violent turmoil of war. The mention of the great peaceful people evokes a sense of innocent tranquility that is about to be disrupted by the horrors of war.
Moreover, the context of this message delivered after years of European conflict and on the brink of American involvement, combined with the moral gravity of the situation described, is designed to move listeners and gentle their resolve for the forthcoming challenges of World War I. It capitalizes on the united patriotism felt by Americans, acknowledging the sacrifice that the nation is about to make.