Final answer:
Abraham Lincoln was initially hesitant to call for abolition, fearing it would cause the Union to split. He prioritized the preservation of the Union over immediate emancipation, eventually moving toward abolition as a strategic necessity during the Civil War, resulting in the Emancipation Proclamation and later the Thirteenth Amendment.
Step-by-step explanation:
One reason Abraham Lincoln did not initially call for the abolition of slavery was his concern for the preservation of the Union. Lincoln's priority during his presidency was keeping the nation together, which he believed could be jeopardized by the immediate emancipation of slaves. Early in the Civil War, Lincoln considered various proposals and preferred a gradual approach to ending slavery, often coupling his ideas with compensation to slaveholders and colonization schemes for African Americans.
It was not until the Civil War progressed that Lincoln issued the Emancipation Proclamation, which declared freedom for slaves in the Confederate states that did not return to the Union by January 1, 1863. This action, however, was as much a strategic war measure as a moral stance. The Proclamation did not free all slaves immediately; it applied only to territories in active rebellion against the Union. Lincoln's approach evolved over time, balancing political pragmatism with moral considerations and the shifting tides of the war. The ambitions of the abolitionist movement and the pressing needs of African Americans escaping slavery influenced Lincoln's policies, culminating in the eventual push for the Thirteenth Amendment, which abolished slavery throughout the United States.