Final answer:
Henry Clay's American System in the 19th century established high tariffs, a national bank, and internal improvements to unify and strengthen the U.S. economy, but also faced criticism for favoring the elite and intersecting with the divisive issue of slavery.
Step-by-step explanation:
In the first half of the 19th century, Henry Clay's American System led to a significant transformation in American economic policy. This comprehensive economic plan, spearheaded by Secretary of State Henry Clay, aimed to strengthen and unify the nation's economy through three main components: high tariffs to protect American industry, the establishment of a national bank to stabilize the currency and provide credit, and federally sponsored internal improvements such as canals and roads to facilitate transportation and trade.
President John Quincy Adams, once in office, adopted Clay's system and extended its vision to include educating future leaders via a proposed national university and naval academy. Nonetheless, critics of Adams' and Clay's policies saw these initiatives as favoring a small, elite group, thus sparking significant political opposition.
Clay's commitment to national economic development occasionally came into conflict with the issue of slavery. Although a slave owner himself, Clay proposed measures like the admission of California as a free state in an effort to balance the interests of free and slave states and maintain national unity. The American System had a lasting impact on the nation's economy and political landscape, influencing the development of the Whig Party and setting the stage for future sectional conflicts.