The term ‘Scotch-Irish’ represents the combination of three identities: the Scottish and Irish in an American setting. In Ireland, Irish Protestants were members of different groups with varied backgrounds and traditions. The Ulster Scots were relatively recent settlers in Ireland, ‘planted’ in Ulster starting in the early seventeenth century. Their experiences with cultural adaptation were similar to what they would later encounter in the American colonies and republic. The difference of experience between those who settled in the southern backcountry in the early eighteenth century and those who joined the California gold rush in the mid-nineteenth century would have been drastic. In addition to their diverse origins and migration experiences, their language, mobility, and adaptability within American society made the Scotch-Irish a particularly difficult group to define. This was especially the case as the characterization of ‘Scotch-Irish’ widened to include all Irish Protestant immigrants and their descendants, regardless of denomination or region of origin.

Historians of ethnicity emphasize the reciprocal interactions between immigrants and their host societies, as immigrants navigated the dynamic ground between ethnic resistance and assimilation. In the United States, as Kevin Kenny describes, ethnicity assumed a historical importance as immigrants emphasized their ethnic identities to become more fully ‘American’. The role of ethnicity fluctuated depending on the challenges a particular ethnic group presented to assimilation and acculturation to American society. The Scotch-Irish, for example, would have been affected when the mood of the country was anti-Irish or Anglophobic.

As the volume of United States immigration increased throughout the latter half of the nineteenth century, both American and ethnic identities were expressed through civic and associational culture. Associational culture became an increasingly important part of American civic life culminating in a ‘golden age of fraternity’ after the Civil War. Many Americans expressed their individuality through joining what Jason Kaufman describes as ‘self-segregating’ organizations based on gender, race, ethnicity, or religion. At times these associations allowed ‘friends’ to join who did not claim membership of that ethnic group, such as Henri Le Caron's Clan-na-Gael participation.

In the mid-nineteenth century, expressions of ceremonial citizenship were changing. As Mary Ryan describes, during the first half of the century major American cities spawned hundreds of voluntary organizations, leading to the pluralization of civic society.