Letters tell the tale of two nations

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.

The exhibit - Pacific Exchange: China and 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, with a letter from Massachusetts to Guangzhou.