Golden Gate & Bay Bridge under constriction.
Golden Gate Bridge:
Construction began on January 5, 1933. The project cost more than $35 million, and was completed ahead of schedule and $1.3 million under budget. The project was finished and opened on May 27, 1937.https://en.wikipedia.org/wiki/Golde...cite_note-33
San Francisco–Oakland Bay Bridge:
Construction began on July 9, 1933. The bridge opened on November 12, 1936, at 12:30 p.m., six months before the Golden Gate Bridge. The total cost was $77 million. https://en.wikipedia.org/wiki/San_F...d_Bay_Bridge
The cards are unused, with a notation of 2/15/36 on the back.