Lucy Ann and Dabney Walker didn't have to risk their lives to spy for the Union army. The couple had already risked everything to escape slavery themselves. But in early 1863, in the midst of the Civil War, the couple was determined to help defeat slavery for everyone-no matter the risk. Together, they created a secret code disguised as laundry on a clothesline. Their plan was incredibly dangerous: it required Lucy Ann to sneak into Confederate...