A devout Quaker who became a passionate poetic spokesman for the antislavery movement, John Greenleaf Whittier (1807-92) was one of the most beloved American poets of his era. In the years before the Civil War, he campaigned tirelessly against slavery in poems that include "Ichabod," his famous denunciation of Daniel Webster for his support of the Fugitive Slave Law. In the long poem "Snow-Bound" (1866) he created a warm and enthralling portrait of...