“San Francisco in 1900 was a Gold Rush boomtown settling into a gaudy middle age…. It had a pompous new skyline with skyscrapers nearly twenty stories tall, grand hotels, and Victorian mansions on Nob Hill…. The wharf bristled with masts and smokestacks from as many as a thousand sailing ships and steamers arriving each year…. But the harbor would not be safe for long. Across the Pacific came a...