The institution of slavery as it existed in the United States from the early 17th century until 1865. It existed in all English mainland colonies and dominated the agricultural production mostly in South. Eight of the first 12 presidents of the United States were slave-owners.
The system of checks and balances laid down by the doctrine of Separation of powers in US constitution prevents the misuse of power given to the institutions. The powers to run the affairs of the USA are divided among three branches;
Andrew Jackson, the only US President to be veteran of revolutionary war and war of 1812, was the 7th President of America as a result of elections of 1828.
Sectional conflict between the two regions i.e. North and South regions was symbolic of the changes in both the regions. South was mainly an agrarian plantation economy whereas north was an industrialized region.