Some historians argue that regional differences significantly increased in the united states between 1800 and 1848. support, modify, or refute this contention using specific evidence.

For Thesis: 
In the beginning of the 19th century, the US had a very strong sense of national unity, but between 1800 and 1848, many political, social, and economic factors led the the increasing formation of regional differences

For Economic:
National Unity: 
-Louisiana Purchase
-Transportation Revolution 
Canals, and roads connect east and west

Regional Differences:
-BOTUS
-Industrialization
-(Protective) Tariffs

For Social:

National Unity:
-Benevolent Empire
-Removal of Indians

Regional Differences:
-slavery/abolition
south wanted slavery to work on their plantations, northerners saw slavery as immoral and wanted abolition

For Political:

National Unity:
-War of 1812
-1 party system

Regional Differences:
-growth of second two party system
democrats vs. whigs