Final answer:
Lincoln's unification of the North strengthened the war effort and morale, leading to Union victory.
Step-by-step explanation:
The effect that Abraham Lincoln's ability to unify the bitterly divided North had on the outcome of the Civil War was to strengthen the Northern war effort and morale, which contributed to the Union victory. Lincoln's leadership during the war helped to mobilize resources and citizens, enabling the Union to fully leverage its industrial capabilities and manpower advantage. By issuing the Emancipation Proclamation and promoting the enlistment of African American soldiers, he not only added a moral impetus to the war effort but also bolstered the Union's fighting forces, which was a strategic move that further strengthened the Union's position. Furthermore, his leadership maintained the support of the anti-slavery British public, making it diplomatically difficult for Britain to recognize the Confederacy.
The unity in the North was integral because it allowed the Union to maintain long supply lines and fight on unfamiliar grounds while also dealing with hostile civilians. The North's ability to produce more war materials, move goods quickly, and supply abundant food sustained the Union troops throughout the war. In conclusion, Lincoln's ability to unify the North was a crucial element in the Union's eventual victory over the Confederacy.