Why did Jefferson and his democratic Republican Party oppose policies that favored manufacturing and trade?

The democratic republicans felt they posed a threat to slavery in the south

It is important to note that Thomas Jefferson and his Democratic Republican Party did not necessarily oppose all policies that favored manufacturing and trade. However, they had concerns about the potential negative impact these policies could have on the agrarian economy, particularly in the South.

Jefferson and his party believed in an agrarian society, where independent farmers would be the backbone of the economy. They believed that manufacturing and trade policies, particularly those promoting industrialization and urbanization, could lead to the growth of large cities and a shift away from the agrarian ideal.

In addition to concerns about the agrarian way of life, Jefferson and his party were also worried about the potential consolidation of wealth and political power that could result from industrialization. They believed that manufacturing and trade policies could lead to the rise of economic elites who would wield significant influence over the government, potentially threatening the principles of republicanism and democratic governance.

Lastly, as mentioned in the question, slavery played a significant role in Jefferson and his party's opposition to manufacturing and trade policies. The agrarian South heavily relied on slave labor, and the growth of industrialization and urbanization could potentially undermine the institution of slavery. The Democratic Republicans in the South were concerned that policies favoring manufacturing and trade could lead to an increase in anti-slavery sentiment and potentially threaten the system of slavery itself.

Overall, while Jefferson and his party did not universally oppose all manufacturing and trade policies, they did have concerns about the potential negative consequences these policies could have on the agrarian economy, the concentration of wealth and power, and the institution of slavery.