“The first reliable index of the over-all prevalence of goitre in the USA resulted from the examination of 2 510 701 men drafted for military service during the First World War. Nearly 12 000 men had simple goitre and 31 % of these were rejected because their necks were so large that the collar of the military tunic could not be buttoned around them. The frequency of the disease was greatest among recruits from the States of Washington, Oregon, Montana and Idaho in the north-west and from the region of the Great Lakes. It was least in men drafted from the southern and Atlantic coast states.”
Reference: Kelly, F.C. and W.W. Snedden, “Prevalence and Geographical Distribution of Endemic Goitre,” in “Endemic Goitre” number 44. In ‘WHO Monograph Series.’, Geneva, Switzerland: World Health Organization, 1960, p. 27.