In diffusionist accounts of the Northern Subject Rule (NSR), this subject-verb concord system spread from Scotland via Ulster to North America and elsewhere. Thus, the NSR in Mid-Ulster English dialects of districts originally settled from England is attributed to diffusion from Ulster-Scots. But the NSR was also a feature of dialects of the North and North Midlands, the regions that contributed most of the English settlers to the Ulster Plantation. Since English and Scottish settlement patterns established in the seventeenth century have been reflected in Ulster dialect boundaries since then, the founder principle provides an alternative account of the persistence of the NSR in Northern Irish English. Usage in nineteenth-century emigrant letters indicates that the NSR was as strong in English-influenced dialects of Mid-Ulster as in Ulster-Scots and suggests that the NSR in Ulster may be a direct import from England as well as Scotland. and Ireland. Areas settled mainly by Scots, Ulster-Scots from the North of Ireland (often Scotch-Irish in American usage), and English still differ in dialect lexicon and features of phonology, morphology, and syntax in ways that can be traced back to their regional roots across the Atlantic (see, e.g., Wolfram & Schilling-Estes, 1998:102-107). As shown in the map in Figure 1, the boundaries between the major varieties of Northern Irish English (NIE) reflect the linguistic influence of English and Scottish founder populations, in that relatively English (Mid-Ulster) and Scottish (Ulster-Scots) dialects are found in parts of the province settled in the seventeenth century from England and Scotland, respectively (Barry