Andrew Jackson was known for being anti-Native American. He signed the Indian Removal Act which was an act of ethnic cleansing. The act was struck down by the Supreme Court, but Jackson illegally exceeded his authority and ordered the military carry it out anyway. It resulted in the deaths of over 4,000 Cherokees on the "Trail of Tears." Andrew Jackson is currently portrayed on the U.S. $20 bill.
Barack Obama is the current President of the United States and the first African American President. He is not portrayed on any U.S. currency.