Not to replace Andrew Jackson on the 20 dollar bill with Harriet Tubman

Harriet Tubman was a saint and did amazing things for slaves in the 1820's with the underground railroad, but she did not do something that changed the very foundation or future of the United States of America. Andrew Jackson had his short comings as a leader and a president, but you can not argue his impact on securing the Mississippi River with the Battle of New Orleans and ousting the French from American soil. He was a founding father that helped expand the country and maintain control of the Eastern US that allowed for future expansion west. So when you look at currency why would you remove a founding father who had such a huge impact on the founding of this country and replace it with someone who, no doubt was a great human being, but did not found this country.