Nationalism is defined as feelings of pride and loyalty for a nation whereas sectionalism causes disagreements between different regions. This maybe due to sharing of natural resources like gasoline, coal, lumber, energy and water.
United States of America as a whole benefits from nationalism, as resources are shared and the nation is economically self sufficient. Nationalism is the choice for the United States of America as it unites the entire nation. It is one nation and not many sections that will compete and cause conflict, as each state will try to compete with the other.
Under one nation, in case of an emergency, the federal government can step in to declare an area under flood as natural disaster