Harriet Beecher Stowe opposed slavery with a passion, but she was a housewife with six children. What could she do? "You can write," her sister-in-law said. So she did. In 1852 her novel "Uncle Tom's Cabin" was published, and Harriet became an instant celebrity. This shouldn't have been surprising. Harriet was a Beecher, and all the Beechers made names for themselves. Her father, Lyman Beecher, was the most renowned preacher in America, but he didn't...