Final answer:
The term 'blood-stained gate' in Frederick Douglass's work symbolizes the Civil War, highlighting the sacrifices made to end slavery and transform the nation's moral conscience.
Step-by-step explanation:
In Blood Stained Gate by Frederick Douglass, the term "blood-stained gate" symbolizes the Civil War. This is evident from the historical context in which Douglass was writing. He evokes the numerous battles and the tremendous sacrifice that African Americans and the Union Army made for the cause of ending slavery in the United States. The violence and the bloodshed during this period were key to transitioning America from a divided nation to one striving for a new definition of freedom that included former slaves. Therefore, the "blood-stained gate" is a powerful metaphor representing the grim yet transformative passage through the Civil War that led to the abolition of slavery and a profound shift in the moral conscience of the country.