Belle Boyd was one of the Confederacy's most well-known spies. She first attracted the notice of occupying Union troops in her hometown of Martinsburg, Virginia, in July 1861 when she shot and killed an abusive soldier for attempting to replace the Confederate flag at her house with the Federal banner. As a result, Union guards were detailed to protect the property. In the months that followed, Boyd, who was not yet twenty, took full advantage of being in the midst of Yankees to eavesdrop and gather military information, which she smuggled, sometimes personally, to nearby Southern camps. Boyd's derring-do led to her arrest and imprisonment on several occasions and won her notoriety in both the South and North. In May 1864, Boyd sailed to England, became an actress, and published her memoirs, Belle Boyd in Camp and Prison (1865).