One of the leading figures of the democratic party in the 1850s was

Martin Van Buren was one of the leading figures

Explanation:

In the 1850s the democatic party was run by president Andrew Jackson. Buren also ended up becoming the 8th president of america after Jackson.

During 1880 to 1860, The United States of America went through social, political and economic changes, which affected the North and South in different ways. The economy of the South depended primarily on slaves. Its settlers had plantations of cotton, which was very profitable at that time, but they needed a cheap labour force to work their lands (slaves). Living in the South meant either having a lot of money to invest on lands (for crop plantations) or working in the only available jobs, which were done by slaves. Since not everyone was able to afford high amounts of money or willing to do slave work, many decided to migrate to the North so as to find job opportunities there. These facts lead to differences in terms of population: the North grew much faster than the South. Besides, black population was concentrated in the South for its economy depended on black slaves. The economy of the North was through commerce, industry, finance and manufacturing. Hence, its economy was much more versified and many different jobs became available: farmers, merchants, millers, manufacturers, mechanists, etc. Since the economic activity was better and grew faster, the North became the most populated region of the States and therefore, more urbanized and industrialized than the South. Due to the fact that there were almost no slaves in this region, white population grew more here.

Explanation: