Popular history tells the story of how the tea boycott during the American Revolution caused a transition in American taste from tea to coffee, making the young country a coffee-drinking nation. In truth, Americans did not give up their tea so easily, and the United States grew to be the second-largest importer of tea from China. Diverging from British black tea traditions, U.S. consumers preferred green tea, cultivated a particular taste for Oolong tea, and invented the English Breakfast Tea brand to market Chinese black tea. This World in a Teacup is the first book to detail the American tea trade with China after the American Revolution through the early twentieth century. Drawing on archival sources and perspectives from both sides of the Pacific, Dan Du offers new insights to help understand fundamental developments in U.S.-China relations within a global context. This World in a Teacup shows that, rather than depending on hard-money transactions or a barter economy, a sophisticated credit system buttressed American tea purchases in China: credit instruments such as promissory notes, bills of exchange, and checks financed the transactions between Chinese and U.S. tea merchants, crystallizing changing power dynamics in the global economy. This World in a Teacup explains how the circulation of these credit instruments challenged the conventional understanding of China's economy as a primitive system and how the power structure of American, British, and Chinese tea trade in the credit economy reshaped American consumption patterns.