Harriet Tubman was an American abolitionist and Union spy.
Tubman in the Timeless Universe
When the time team, consisting of Lucy Preston, Rufus Carlin, Wyatt Logan, and Garcia Flynn, first arrived to 1863, and saw how the Rittenhouse sleeper agent, Ryerson, used his knowledge of the future to stop what was a successful attack in the original timeline, they were spotted by Harriet Tubman. After Tubman performed a mercy killing for one of her troops, Wyatt explained to Tubman, dishonestly, that General George McClellan and Colonel James Montgomery sent them to help with the raid. Tubman went onto explain that Montgomery had all of his troops retreat after seeing how proficient the Confederates were, but that she would perform the raid with whatever men she had. She wanted to continue the raid even when Wyatt warned Tubman about a Confederate spy, and threatened Wyatt with death if he planned to impede her.
Later, Harriet Tubman can be seen helping hurt soldiers with herbal remedies. Lucy explains to Flynn that Tubman had a lot of experience in many aspects of the military, but would die in poverty after failing to get a military pension. Samuel then arrives after scouting out the Willow Glen Plantation, explaining that there are many slaves there, but also many Confederates. Tubman decides to take the risk, and try to free the slaves with the few men they have, but Lucy warns her that the spy will make this a fruitless en-devour. Flynn and Lucy then leaves to convince Colonel Montgomery to provide Tubman with reinforcements. Tubman isn't convinced they will be able to get reinforcements.
Later, when Wyatt, Rufus, and Tubman are preparing for the raid, Tubman realizes she saw Wyatt and Rufus in a dream that God had delivered onto her.
Isaiah informs Tubman that an unknown event is going on at the plantation, so Rufus is sneaked into the event as a house slave to gain information about it. While Rufus was in disguise, Harriet and her troops were noticed by a Confederate, who alerted those at the plantation. He was shot and killed by Harriet Tubman. After a fight with Wyatt and Rufus, Colonel Ryerson runs out of the plantation only to be shot and killed by Tubman with Colonel Montgomery's reinforcements behind her.