The second and most dramatic boom and bust resulted from the Klondike Gold Rush, which ended the depression that had begun with the Panic of 1893; in a short time, Seattle became a major transportation center. On July 14, 1897, the S.S. Portland docked with its famed "ton of gold", and Seattle became the main transport and supply point for the miners in Alaska and the Yukon. Few of those working men found lasting wealth, however; it was Seattle's business of clothing the miners and feeding them salmon that panned out in the long run. Along with Seattle, other cities like Everett, Tacoma, Port Townsend, Bremerton, and Olympia, all in the Puget Sound region, became competitors for exchange, rather than mother lodes for extraction, of precious metals. The boom lasted well into the early part of the 20th century and funded many new Seattle companies and products. In 1907, 19-year-old James E. Casey borrowed $100 from a friend and founded the American Messenger Company (later UPS). Other Seattle companies founded during this period include Nordstrom and Eddie Bauer. Seattle brought in the Olmsted Brothers landscape architecture firm to design a system of parks and boulevards.

After lumbering, what was Seattle's second big economic boom?