A man with a 1933 Packard on the trestle to the South Tower during the beginning of the construction of the Golden Gate Bridge, San Francisco, California, August 1933. (Photo by Underwood Archives/Getty Images)

View of the Marin Tower of the Golden Gate Bridge under construction, San Francisco, California, 1934. (Photo by Underwood Archives/Getty Images)

The Golden Gate Bridge under construction with two workers on the saddle atop the Marin Tower, 746 feet above the water, San Francisco, California, 1934. (Photo by Underwood Archives/Getty Images)

One of the stanchions erected in the building of the Golden Gate bridge, connecting Marin and San Francisco, casts a shadow over houses at its foot, circa 1935. (Photo by General Photographic Agency/Getty Images)

Construction of the Golden Gate Bridge, at the time the longest chain bridge of the world. San Francisco, around 1935. (Photo by Imagno/Getty Images)

The Golden Gate Bridge under construction with the Pylon #1 and the North and South Towers rising above Fort Point, San Francisco, California, April 1935. (Photo by Underwood Archives/Getty Images)

The Golden Gate Bridge under construction with riveters at work in cages on the South Tower, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

View from over the Marina and the Presidio of the Golden Gate Bridge under construction with the Palace of Fine Arts in the lower center, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

Chief Engineer and builder of the Golden Gate Bridge, Joseph Strauss, and Assistant Chief Engineer William Payne, discuss the details of the bridge as the first string of wire was released and sent out across the space where the bridge will be built, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

View of Golden Gate Tower under construction from San Francisco looking towards the mountains of Marin County, California, circa 1935. (Photo by Hulton Archive/Getty Images)

The Golden Gate Bridge under construction with the Pylon #1 and the North and South towers rising above Fort Point, San Francisco, California, April 1935. (Photo by Underwood Archives/Getty Images)

Cables suspended on the Golden Gate Bridge between the towers before being bound together to support the roadbed that will hang below them, San Francisco, California, circa 1935. (Photo by Underwood Archives/Getty Images)

A man standing on the first cables during the construction of the Golden Gate Bridge with the Presidio and San Francisco in the background, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

View of the Golden Gate Bridge under construction, San Francisco, California, circa 1935. (Photo by Hulton Archive/Getty Images)

A worker running up one of the catwalks being built for the construction of the cable of the Golden Gate Bridge, San Francisco, California, September 19, 1935. (Photo by Underwood Archives/Getty Images)

The Golden Gate Bridge under construction with workmen putting the finishing touches on the South Tower, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

A construction worker stands at one end of the catwalks that span the Golden Gate between the two towers, San Francisco, California, December 1935. (Photo by Underwood Archives/Getty Images)

Construction of the Golden Gate Bridge with a view of the catwalks being placed under the cables, 1936. (Photo by Underwood Archives/Getty Images)

Chief Engineer of National Parks Frank Kettredge with his chief counsel George H. Harlan on the Golden Gate suspension bridge in San Francisco, 1937. (Photo by Fox Photos/Getty Images)

The Marin anchorage of the cables for the Golden Gate Bridge that runs between San Francisco and Marin County, Sausalito, California, 1930s. (Photo by Underwood Archives/Getty Images)

Workers on the catwalks bundling the cables during the construction of the cables of the Golden Gate Bridge, San Francisco, California, circa 1936. (Photo by Underwood Archives/Getty Images)

View from Crissy Field in the Presidio of the construction of the Golden Gate Bridge with the roadbed being installed, San Francisco, California, 1937. (Photo by Underwood Archives/Getty Images)

Construction of the Golden Gate Bridge with men on the catwalks working on the cables, San Francisco, California, 1937. Alcatraz Island can be seen in the background. (Photo by Underwood Archives/Getty Images)

A workman walks on the levee that connects Fort Point to the south tower of the Golden Gate Bridge while it is under construction, San Francisco, California, October 1936. (Photo by Underwood Archives/Getty Images)

High-angle view of traffic and pedestrians using the Golden Gate Bridge, San Francisco, California, circa 1937. (Photo by Hulton Archive/Getty Images)

A US Navy aircraft carrier going under the Golden Gate Bridge during opening day ceremonies for traffic on the bridge, San Francisco, California, May 28, 1937. (Photo by Underwood Archives/Getty Images)

Press cars going across the about to be opened new Golden Gate Bridge, San Francisco, California, May 24, 1937. (Photo by Underwood Archives/Getty Images)