The introduction of iodized salt in the 1920s dramatically reduced rates of in the united states.

The introduction of iodized salt in the 1920's dramatically reduced rates of goiter in the United States. This rapidly reduced the incidence of iodine deficiency. The United States and Switzerland were the first two countries to introduce the use of iodized salt to their country. 

warfare was the primary means of cultural transmission in both regions.

to keep us neatruel and not get involved in any wars

he assumed control of treaty negotiations with a hostile power