What caused many northerners to be more aware of the human cost of slavery

"The Novel Uncle Tom's Cabin"

Explanation:

Harriet Beecher Stowe

In 1851, she began publishing her novel Uncle Tom’s Cabin serially in The National Era, an anti-slavery newspaper published in Washington, DC. The book sold 300,000 copies in the US in the first year of its publication, and an estimated 1,000,000 in the United Kingdom. Except for the Bible, it is estimated that it outsold every other book published in English during the nineteenth century.

The book humanized slavery to its readers. The characters were believable, the incidents neither better nor worse than reported in other sources, and the plot appealing to the tastes of the era. Now when people heard about slaves, they thought of Uncle Tom and Eliza, people about whom they cared.

- Original post from Jim Wayne, B.A. from Duke University (1967)