The Smithsonian National Postal Museum in Washington DC is telling the story of China-US relations through its huge collection of Chinese and US postage stamps and mail. Opening today, the exhibit - Pacific Exchange: China & US Mail - displays collections that are usually in the museum's vault and have never been shown to the public before. Organized into three themes - commerce, culture and community - the exhibit includes stamps and mail from as early as 1849, as the front of a Massachusetts-to-Guangzhou letter suggests. Besides stamps and mail, the exhibit also tells stories of the early part of the exchange, when the Qing Dynasty court hired two American engravers to set up a Chinese bureau of engraving and printing so that China could start to produce its own stamps and currency. Chinese people in America is another theme in the exhibit, highlighting the people who came to the US for the California gold rush that began in 1849 and as workers on the transcontinental railroad as well as farming in Hawaii, which was then an independent monarchy. Yet, as the exhibit shows, the fate of Chinese immigrants took a dramatic downturn when the racist Chinese Exclusion Act was passed in 1882.