The Alaska-Yukon-Pacific Exposition was an world's fair held in Seattle in 1909, publicizing the development of the Pacific Northwest.
The fair was set up on the grounds of the University of Washington, which mostly undeveloped at the time. The layout of the Exposition and its buildings were partly funded by the state legislature, so that they could be used later by the University. Two of the buildings are still in use as of 2003, although most were poorly built and have long since been replaced.
The United States Post Office Department issued a 2-cent postage stamp for the Exposition, depicting a profile of William Seward and inscribed "ALASKA-YUKON-PACIFIC-1909". At the request of several private vending machine companies, the stamp was also issued imperforate; these were sold at the show by the companies as a promotion. In addition, two machine cancellations were devised: one a flag cancellation including the words "ALASKA-YUKON-PACIFIC / EXPOSITION", and the other, a straight-line design reading "WORLD'S FAIR / SEATTLE / 1909".