Join Ranger Tim of the Harriet Tubman Underground Railroad National Historical Park on a free walking tour around downtown Cambridge, Maryland and discover the stories of the Underground Railroad and the people associated with Harriet Tubman’s life. From 1 to 2:30pm on July 30. Meet outside in front of the Harriet Tubman Mural at the Harriet Tubman Museum & Educational Center, 424 Race St., Cambridge. For more information, contact Ranger Tim at 443-205-1933. Wear comfortable shoes and bring a bottle of water.