Sarah Emma Edmonds was a nurse, soldier and Union Army spy. In the summer of 1862, she suffered the death of a soldier, with whom she was deeply in love. At this time, she was a nurse, tending the battlefield's wounded and dying. A Confederate sharpshooter, during the second battle of Bull Run, killed her lover on August 30. Since that day, she was no longer content to be a nurse. Instead, she began gathering vital information for the Union Army as a spy, regarding activities of the Confederate forces.

Sarah's first act of espionage involved disguising herself as both a man and a woman. She prepared for the transformation for three days. She bought work clothing much like those worn by the slaves, she cut her hair very short and close to the scalp, and she used burnt cork to blacken her face, hands and arms. She also purchased a black wig, which was difficult to get in those days. However, when she appeared in full disguise, at Union General McClellan's camp, she gathered some crackers, a loaded pistol and set out for the Confederate camp.

At midnight, she reached her destination and rested on a bed of leaves. The next morning, African American slaves, bringing breakfast to the guards, awakened Sarah. She made their acquaintance and when they returned, she followed them inside the Confederate fortifications. She fell in with the other slaves, working and pushing wheel barrels filled with gravel. At night, despite fatigue, she roamed the Confederate camp, making sketches of the camp and its surroundings, and making notes of the number of soldiers and the cannon sizes.

The next day, Sarah changed places with another slave supplying drinking water to the troops. She managed to gather information about the arrival of General Joseph E. Johnston and the number of reinforcements expected. The most staggering information was that Confederate forces would secretly leave Yorktown and retreat toward Richmond. On the third night of her spying, she quietly slipped through the lines, bringing this information to General McClellan. This vital data helped the Union General plan his attack.

Sarah became a "master of disguises". She not only convinced the US Army that she was a man named, Franklin Thompson, but she fooled others in believing she was a black man, an Irish peddler woman, a black laundress, and a young man from the South. For two years, Sarah Edmonds ran esionage missions, under various disguises, for the Union. So exceptional were her efforts, that credit was initially bestowed on her alter ego, Franklin Thompson.

She was transferred to General Grant's army in 1863, to prepare for the battle at Vicksburgh, still serving as Private Thompson. She returned to nursing in the military hospital where she contracted malaria. She deserted the Army, rather than reveal her true identity, and finished the war as a civilian nurse.

Twenty years passed before she asked her fellow soliders for help in obtaining a pension and recognition. It was then, the men realized that Private Thompson was actually a woman.

A special act of Congress was granted, on July 5, 1864, for Sarah Emma Edmonds, who was now known by her married name of Sarah E. Seelye.

She received and honorable discharge from the Army and a pension of $12.00 a month.