The correct answer is The American system.
Henry Clay was a Congressman and Secretary of State at one point. His economic policies were extremely influential in the development of America during the early-mid 19th century. Henry Clay developed the American system in hopes of helping America to become more industrialized and successful.
For example, implementing high tariffs would increase the price of foreign goods, making citizens more likely to buy goods made in the US. Increasing railroad availability and transportation methods would help to increase trade across the country.