Harriet Tubman changed the world by escaping from slavery, becoming an abolitionist and helping many slaves attain their freedom by means of the Underground Railroad, a secret network of routes and safe houses to aid runaway slaves. Later in life, she helped John Brown plan his raid on Harper's Ferry and assisted the Union army during the Civil War as a scout, spy and nurse.
Land was needed to gain power so the need for bigger, stronger ships was needed so that they could be sailed through the rough oceans without being sank to reach land
