Jackson opposed the bank of the United States because he felt it

He thought it was unconstitutional and that it favored the rich.

Andrew Jackson opposed the National Bank b/c he thought it was unconstitutional and it gave too much economic power to capitalists. Also, the National Bank could control the state banks. The national banks could demand gold and silver from the state banks, reducing their reserves and forcing them to reduce the value of their paper money. If the national banks didn't demand gold and silver, the state banks would have larger reserves, increasing the value they could put on their paper money. In addition, the National Bank was paying to have certain men elected or maintain a position in Congress.