Click on the links to take you to the Brain Pop sites. The Harriet Tubman lesson is from Brain Pop Jr., and Slavery is from the Brain Pop site. Choose according to your class' age appropriateness.
You may have to login, using the free 30 day account trial that your numeracy rep provided for you. If you forgot to sign up, you can use the login of another teacher in your school that did sign up.
Again, not exactly math related, but the more you use Brain Pop, the more you'll come to discover the advantages of the program. And, as those at Brain Pop say, "The more you know, the more you know."