When pioneers arrived in Seattle in the 1850s, Lake Union history was already underway, as the area was inhabited by Native Americans (Duwamish or Southern Coast Salish). Their camp was in the southwest corner of the lake, near where Thomas Street and 8th Avenue North meet just north of Denny Park. That area and the part of South Lake Union that lies east of Fairview Avenue North was known by white settlers in Seattle as “Cascade”, however, that area has since become known as part of the South Lake Union region of Seattle. A significant number of native inhabitants continued to reside in South Lake Union until 1875.
In 1853, David Denny (one of Seattle’s earliest settlers) staked a claim on the South Lake Union area along what is now Denny Way. A sawmill (bought by Denny and named the Western Mill) was built near the current-day intersection of Mercer Street and Westlake Avenue in 1882, eventually serving as a sawmill for logs that were floated through the canal from Lake Washington.
David Denny went bankrupt in 1895, after which the Western Mill was turned over to the Brace/Hergert Mill Company and operated by them until the 1920s. Brace & Hergert built the peninsula into the lake now known as South Lake Union Park for an extension of their mill in 1909. Brace & Hergert turned into Brace Lumber Company and continued to operate in South Lake Union until 1988.
Through the late 1890s and into the 1900s, Lake Union saw plenty of other growth in buildings and manufacturing. Boeing’s seaplane manufacturing plant was in the area, along with Seattle City Light’s Hydro House, the Lake Union Steam Plant (now used by Zymogenetics), and the Ford Model T assembly plant – the first west of the Mississippi.
The opening of the Lake Washington Ship Canal in 1917, with the Ballard locks to keep Lake Union at its historic level, continued to grow the neighborhood’s industrial and commercial development.
Paul Allen, Microsoft co-founder, donated $20 million to buy South Lake Union for the Seattle Commons in the early 1990s. Ownership reverted to him in the later years of the decade after public votes defeated proposals for the Commons to redevelop the neighborhood to become something like New York’s Central Park. Allen’s real estate company, Vulcan, has since been involved in the Mercer Corridor construction projects, as well as selling or leasing much of the property and later built retail and residential space in the developing neighborhood.
Amazon.com consolidated its offices to South Lake Union in 2010, and the Museum of History and Industry moved its location from the Montlake neighborhood to South Lake Union’s former Naval Reserve Training Center.