This analysis applies genetic and linguistic distance measures to pronunciations of 82 different phonemes (with a total of 285 allophones)
by 131 speakers in regions of the South, Massachusetts, and southern England, drawn mainly from Kurath and McDavid's Pronunciation of English
in the Atlantic States. Speakers are compared by counting shared allophones, by calculating Nei's genetic distance from the proportion of shared
allophones, and by calculating a Euclidean distance between allophones in a standard idealized vowel grid. The alternative measures provide
insights into speech variation within and among regions that complement but do not replace those from a careful analysis of individual
speech features. The results suggest that differences among American speech forms may be accounted for largely by founder effects that
culled different sets of allophones from the large population available among early immigrants from different regions of England.