The argument presented in the excerpt is that the American System, as envisioned by political leader Henry Clay in the 1820s, would serve as the basis for social improvement. This system involves the federal government using revenue from the sale of its land holdings to subsidize internal improvements.
Additionally, protective tariffs would be imposed to foster the development of American manufacturing and agricultural enterprises, especially those in their infancy and vulnerable to foreign competition. The promotion of industry is seen as a means to create a domestic market for agricultural commodities, reciprocating the existing market for manufactured products from farms.
(B) A group that would challenge the ideas of the excerpt is the states' rights advocates or proponents of a strict interpretation of the Constitution. This group, often associated with the Southern states, opposed the expansion of federal powers and intervention in economic affairs. They believed in a limited role for the federal government and argued that such intervention, as proposed by the American System, encroached upon states' rights and individual liberties.
States' rights advocates were concerned that protective tariffs and federal subsidies for internal improvements would disproportionately benefit certain regions or industries at the expense of others. They argued that these measures went beyond the enumerated powers granted to the federal government by the Constitution and that such economic interventions should be left to individual states. The opposition stemmed from a broader philosophical and political disagreement about the appropriate scope of federal authority and the balance between state and national interests.