Allan Pinkerton, head of the new secret service agency of the Federal government, places Confederate spy Rose O'Neal Greenhow under house arrest in Washington, D.C.
Greenhow was a wealthy widow living in Washington at the outbreak of the war. She was well connected in the capital and was especially close with Massachusetts Senator Henry Wilson. The Maryland native was openly committed to the Southern cause, and she soon formed a substantial spy network.
Greenhow's operation quickly paid dividends for the Confederacy. One of her operatives provided key information to Confederate General Pierre G. T. Beauregard concerning the deployment of Union General Irwin McDowell's troops before the First Battle of Bull Run, Virginia, in July 1861. Beauregard later testified that this dispatch, along with further information provided by Greenhow herself, was instrumental in Beauregard's decision to request additional troops. The move led to a decisive victory by the Rebels.
It did not take the Federals long to track down the leaks in Washington. Pinkerton placed Greenhow under house arrest, and he soon confined other suspected women in her home. However, Greenhow was undeterred. She was allowed visitors, including Senator Wilson, and was able to continue funneling information to the Confederates. Frustrated, Pinkerton finally confined Greenhow and her daughter to the Old Capitol Prison for five months in early 1862. In June 1862, she and her daughter, "Little Rose," were released and exiled to the South.
Greenhow traveled to England and France to drum up support for the Southern cause, and she penned her memoirs while abroad. She was on her way back to America in September 1864 when a Yankee war vessel ran her ship aground in North Carolina. Weighted down by a substantial amount of gold, Greenhow's lifeboat overturned and she drowned.