Though she’s most famous for her role as a conductor on the Underground Railroad, Harriet Tubman — better known as “Minty” to her loved ones — wore many hats throughout historic life, including a covert one: Civil War spy. She took on the role at the behest of Massachusetts Governor John Andrew, an abolitionist who formed the all-Black 54th and 55th Massachusetts Regiments. 

Tubman’s experience rescuing enslaved people in the years before the Civil War resulted in a wealth of invaluable geographical knowledge that proved critical on numerous scouting expeditions; she also recruited and trained informants, many of whom were formerly enslaved. Her greatest contribution to the Union effort came in 1863, when she helped lead an operation that liberated more than 700 enslaved people in South Carolina.

That operation, known as the Combahee Ferry Raid, took place on June 2, 1863. Tubman became the first woman in American history to plan and lead a military raid, doing so with the help of about 150 Black soldiers. Many of the people who were emancipated during the raid later joined the Union Army themselves. In a letter written to General Quincy Gillmore on July 6, Montgomery wrote, “I wish to commend to your attention Mrs. Harriet Tubman a most remarkable woman, and invaluable as a scout.” Tubman came to be known as the “Moses of Her People” for her tireless work before and during the Civil War.