In this instance, Douglass explains that many Northerners mistakenly believe that the singing of slaves is evidence of their happiness. He says that the songs are actually evidence, on an almost subconscious emotional level, of the slaves' deep unhappiness.
He became a leader in the abolitionist movement, which sought to end the practice of slavery, before and during the Civil War. After that conflict and the Emancipation Proclamation of 1862, he continued to push for equality and human rights until his death in 1895.
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