What part of the American system was opposed by presidents Madison and Monroe Why?

Presidents James Madison and James Monroe opposed the American System, particularly its emphasis on a strong federal role in economic development through tariffs, a national bank, and internal improvements. They believed that such centralization could threaten states' rights and lead to excessive federal power. While both supported infrastructure development, they preferred a more limited federal involvement, emphasizing the importance of state sovereignty and individual liberties. Their opposition reflected a broader concern about balancing federal authority with states' rights in the post-Revolutionary context.