Kroll's Downtown Seattle, Summer of the Floating Bridge

The bridge in question is the Lacey V. Murrow Memorial Bridge, dedicated July 2, 1940 — the world's first large-scale concrete-pontoon floating bridge, carrying what would become US Route 10 (later Interstate 90) across Lake Washington on hollow concrete floats rather than piers. The map's sidebar calls it a "unique structure," which was an accurate understatement: nothing like it had been built before.

Kroll Map Company, founded in Seattle in 1911 by Austrian immigrant Carl Kroll, had absorbed several predecessor cartographic firms by 1940 and was the dominant commercial mapmaker in the Pacific Northwest. Producing promotional street maps for the Chamber of Commerce was squarely in its wheelhouse: the Chamber, founded in 1882, was actively marketing Seattle as a modern destination throughout the Depression and war years.

The right-hand column functions as a condensed tour guide — eight Seattle landmarks, each keyed to a lettered grid square on the map. Two entries are especially time-sensitive. The Show Boat Theatre was a WPA-built replica Mississippi steamboat on the Lake Washington Ship Canal, housing the University of Washington's drama department since 1938. The Penthouse Theatre had just moved into its new purpose-built home in May 1940 — the first true theater-in-the-round (audience seated all around a central stage, no fixed front) in the United States. Both were on the UW campus, not downtown, but the Chamber was selling the whole city.

The red-framed box at lower right is the candid moment. Seattle was mid-overhaul, swapping its aging streetcar rails for trackless trolleys (electric buses that draw from overhead wires but roll on rubber tires, no tracks) and motor buses. The notice admits outright that schedules are unavailable, and directs confused visitors to call the Transit Commission. The last Seattle streetcar ran April 13, 1941 — so anyone who picked up this map at the Chamber counter was navigating a city whose transit network was being dismantled as they read.