Serendipity ... I stumbled across a summary of his talk while Googling for something else. Since I had no idea that Americans had even tasted green tea prior to the late twentieth century, it was a revelation!
Here are the most intriguing bits:
Someone, in summarizing the talk, wrote: In 1882, 46.5 m. lbs. of tea were produced in Japan, of which 36 m. were exported. If we estimate that about 4 m. lbs. were lost in the refiring, this leaves only 6.5 m. lbs. for approximately 346 m. Japanese. This raises the interesting question, what were the Japanese drinking at the time?
The next question was, why Americans should have drunk green tea. Coffee was the American drink par excellence, but still green tea was drunk in the Midwest, on the West Coast and in the New York area, especially with the evening meal. Clearly, green tea was regarded as an exotic drink, and this characteristic was emphasized by the Japanese labels on the packets.
In those days coffee was made by boiling the grounds in water for about ten minutes; then eggs and fish were often added to make the grounds settle. Presumably the same method was adopted for making green tea. Mr. Hellyer had experimented with this, and the resulting brew was unbearably bitter; this must account for the fact that Americans added milk and sugar to their green tea, a practice that amounts to sacrilege in Japan ("How revolting!" was the response he got from Japanese). After the 19th century, the consumption of green tea in the U.S. declined (...)
In conclusion, Mr. Hellyer surmised that the popularity of green tea in America had been due to the influence of its cultural identification with Japan. When the export market eventually declined, the production was absorbed by the Japanese domestic market. This raises an interesting question: did the American taste for green tea lead to its becoming a prevalent daily beverage in Japan?