Hannah Whitall Smith was the spiritual mentor of many, including Catherine Marshall. Born into a Quaker family in Philadelphia in 1832, she grew up tirelessly investigating the religious life. She and her husband, Robert Pearsall Smith, immigrated to England to become one of America's most famous expatriate families. Their lay ministry was known as the Higher Life Movement, and in 1875 Hannah wrote The Christian's Secret of a Happy Life, which originally was conceived as an article for her husband's inspirational magazine. The book became a worldwide bestseller and has influenced generations.