
The Golden Gate Bridge and the Bay Bridge
The Oakland Bay Bridge was inaugurated towards the end of 1936 while the Golden Gate Bridge was opened in the summer of 1937.
The Bay Bridge is known to be the world's longest steel bridge. It's also known to be the most costly single structure ever built. People started using this bridge on 12th November, 1936.
The Golden Gate Bridge was opened to San Franciscans on 27th May, 1937. About 200,000 people walked across it on that day. Vehicles began using it the following day.
http://gocalifornia.about.com/cs/sanfrancisco/a/ggbridge_4.htm
http://en.wikipedia.org/wiki/Golden_Gate_Bridge
http://www.dot.ca.gov/hq/esc/tollbridge/SFOBB/Sfobbfacts.html

