At five years old, a little black girl nicknamed Minty was very busy rocking a white baby. If the baby cried, Minty would be whipped.

That little slave girl grew up strong, compassionate, and clever. She grew up to be Harriet Tubman, the most famous Underground Railroad conductor of all.

Unlike a regular railroad, the Underground Railroad didn’t have a “boss.” An organization didn’t run it. Regular people did. Conductors and escaping slaves also didn’t follow the same route again and again like a train follows tracks. Most conductors didn’t even know about all the other Underground Railroad workers around the country. They only knew what was happening secretly in their own communities.

Where was the railroad? It makes more sense to ask who it was. “Stationmasters” were usually ordinary folks—farmers, pastors, business owners—and their spouses. They hid slaves in homes, churches, and schoolhouses. And their local work . . . worked. The railroad helped move hundreds of slaves to freedom each year.

American slavery was a tragic institution. God designed people to live free. He did not create them to own or mistreat each other. Runaway slaves in the South faced very difficult lives. To escape, they made almost impossible journeys, chased by slave owners and bounty hunters all the way to freedom. But first they had to figure out how to run away. Sometimes black conductors like Mrs. Tubman could help. These conductors would sneak into plantations and then guide others to freedom.

Runaways traveled by night and hid in the daytime. That’s why Mrs. Tubman did most of her conducting in spring and fall. Those seasons have short days, long nights, and good weather for moving on foot.

Once slaves left a station, each stationmaster would message the next one: “Get ready. Someone is coming!” Other people along the railroad helped by giving money. Escaped slaves needed ordinary clothing to replace their slave garb. They sometimes required money to journey by boat or train. And in the North, people helped escaped slaves find homes and jobs.

Like every railroad, there was an “end of the line” for the Underground Railroad. It ended around 1863 during the Civil War. But the work of freeing slaves wasn’t done—not even for Mrs. Tubman. She became a nurse and a spy for the Union Army.