Although, the longest suspension bridge in the world when opened in 1936, the San Francisco Bay Bridge still loomed in the shadow of its iconic sister, the Golden Gate Bridge. Completed within 6 months of each other, the two structures, nicknamed the "Symphonies of Steel," marked the dawning of a new modern era for the Bay City.

Once trains and automobiles began dominating the American landscape, San Francisco's isolated location on the tip of a peninsula required a more direct connection to mainland cities. Concerned over San Francisco losing its status as a commercial capital of the West Coast, city officials saw the twin bridges as a way to ensure the continued prosperity of their community.

Although plans for the Bay Bridge began in the nineteenth century, construction did not commence until 1933. Tasked with accomplishing what many thought impossible, architect and engineer Charles H. Purcell, faced formidable challenges, including earthquake fault lines and extreme winds. To counteract these natural forces, workers drove foundations deeper into the sediment than any other bridge in the world. To further ensure success, planners chose to run the bridge over Yerba Buena Island, located in the middle of San Francisco Bay. This reduced the span lengths and overall stress on the four and half miles of steel and concrete, creating essentially two separate bridges connected to each other.

Opened on November 12, 1936, the bridge's double-decker construction originally separated trucks and railroad cars from private traffic. However, the city later converted the entire structure to automobile use.

One of the most expensive public works projects in the history of the United States, the Bay Bridge's necessity outweighed its price and today 280,000 cars use the bridge each day to move across San Francisco Bay.

Podcast Written and Narrated by Mary Rout, Public History Student at the University of West Florida.