What is an exagerated loyalty to a particular region of the country?

A loyalty to a specific part of the country is known as sectionalism. This is defined by having an interest that narrowly defines the region one is born or lives in with little regard for the nation as a whole. In this country, it may have been at its height during the late nineteenth century, when ideologies and viewpoints were unique to the part of the country one resided in. (I.e., North vs. South during the Civil War).