Final answer:
The allegorical comparisons involving Abraham Lincoln emphasize his essential role as a leader and the profound implications of his death for a nation akin to a crew losing their guiding force in the midst of a storm.
Step-by-step explanation:
The comparison of Abraham Lincoln to a captain, his army to a boat, and the keel to US values, along with likening his death to losing a captain and victory to winning a prized war aim, all serve to illustrate the importance of leadership and unity during times of conflict. As President during the Civil War, Lincoln's steady leadership and belief in the Union's principles guided the country through its most perilous period.
So influential was his leadership that it was equated to that of a ship's captain, navigating the turbulent waters of war. When Lincoln was assassinated, the nation grieved as though they had lost the very person steering them to safety. The struggle for the Union could be seen as a daunting voyage, with victory in the Civil War representing a hard-earned prize after a fearsome journey.