Final answer:
Abraham Lincoln was the moderate who initially supported a gradual end to slavery, which was in contrast to abolitionists like William Lloyd Garrison, who later called for its immediate end.
Step-by-step explanation:
The individual who was considered a moderate and called for the gradual end to slavery was Abraham Lincoln. Lincoln hoped that his lenient plan, which did not require a large percentage of voters to pledge allegiance to the Union or emancipation, would make the end of slavery acceptable and lead to reconciliation. His approach appealed to some in the moderate wing of the Republican Party. However, during this same period, more staunch abolitionists like William Lloyd Garrison adamantly advocated for the immediate end to slavery and racial equality, which highlighted the divide within the anti-slavery movement. Garrison later recanted his earlier stance on gradual abolition and became a prominent voice for immediate emancipation.