Some takes on the Treasury putting Harriet Tubman on the $20:
Tubman was a brave woman and rightly considered a hero. Andrew Jackson was, well, Andrew Jackson. He was a hard, hard man.
But while Tubman is easier for contemporary Americans to identify with, Jackson was a truly pivotal figure in American history. He tossed the British out of New Orleans, added Florida to the Union, championed the rights of frontiersmen, introduced a new level of populism to American government, and founded the Democratic Party.
Love him, hate him, or grudgingly respect him, America would not be the same country without Jackson. There is a reason why we have counties and cities named after Jackson. Tubman is a side character, a footnote in the history books.