"Orange Pekoe" as an advertising slogan

[mbanu]

In America, the "orange pekoe" advertising campaigns by companies such as Lipton and Tetley helped transform the nation from green and oolong drinkers into black tea drinkers almost exclusively, but there is not much information out there on it.

When people try to look, most info goes back to the fuzzy origins of the term as a grade for tea, rather than how it was used in practice, so I thought this might be a good place to post about what the tea was and what it became -- maybe we will even get to the bottom of the original name?