The correct answer to this open question is the following.
The Underground Railroad was not a railroad per se, but a group of people that helped crossed the southern lines to the Northern states, so slaves could escape from the tyranny of the owners of the large plantations of the South. It was the Quakers in the 1800s who started to form this group and helped slaves to escape.
On the other hand, Dred and Harriet Scott were two black slaves that sued for their liberty in the 1840s, claiming they had lived in a free territory. The Supreme Court decision or better known as the Dred Scott decision infuriated many people in the North and was one of the reasons for the beginning of the American Civil War.
I think that the Underground Railroad case was a more effective form of resistance because it made many whites and blacks united for a noble cause, despite they were risking their lives to help black slaves to escape from the southern territory.
