The Public Law that authorized the San Francisco-Oakland Bay Bridge Half Dollar (i.e., "Bay Bridge") called for the striking of up to 200,000 coins. I've written before how there were competing "bridge coin" bills in the House of Representatives and Senate in 1936, with the House bill seeking to commemorate the opening of the Bay Bridge as well as the Golden Gate Bridge, and the Senate bill focused only on the Bay Bridge. (
1936 San Francisco-Oakland Bay Bridge - Redux).
1936 San Francisco-Oakland Bay Bridge Half Dollar

In February 1937, a bill was introduced in the House that called for the re-allocation of 100,000 of the authorized Bay Bridge half dollars to a coin program that would commemorate the completion of the Golden Gate Bridge. In June 1937, the House Committee on Coinage, Weights, and Measures reported the bill favorably with a recommendation for it to pass (with a few minor administrative amendments).
Golden Gate Bridge - Across the San Francisco Bay - Pacific Ocean "Gate"
As a result of the Committee Report, the bill was brought up for consideration in the House. The Committee's amendments were agreed to and the measure was passed easily by the House and sent to the Senate for concurrence. During the following discussion on the Battle of Antietam 75th Anniversary Half Dollar and the Norfolk, Virginia Bicentennial/Tricentennial Half Dollar (also reported favorably by the Committee), John Joseph Cochran (D-MO), a member of the House Committee on Coinage, Weights, and Measures, rose to respond to a question from Jesse Paine Wolcott (R-MI) about Cochran's support for these Committee-reported bills.
Regarding the Bay Bridge half dollar bill specifically, Cochran stated:
"The third bill, the San Francisco Bridge commemorative coin bill, passed in the closing days of the [last] session [1936, 74th Congress, Session 2]. There were two bridges, but the bill as drawn provided for 200,000 coins for one bridge. When an effort was made to amend it, we were advised it was too late. The officials in charge of one celebration agreed to issue only 100,000 coins and kept the promise. Now, this bill provides that the other 100,000 can be issued to commemorate the construction of the second bridge. In view of the understanding in the last session I offered no objection to the favorable report on this bill."The House-approved Golden Gate Bridge bill failed to gain approval in the Senate (it was never reported by the Senate Committee on Banking and Currency) and so the Golden Gate Bridge was never commemorated on a US half dollar as was its San Francisco Bay partner. So, a promise made in good faith by the San Francisco Clearing House Association to cap its "Bridge" coin requests at 50% of what was authorized (100,000 minted of 200,000 authorized) was left unrewarded by Congress as the support for additional US commemorative coins waned within its halls.
I introduced this topic back in 2012:
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Did You Know? #06 - Golden Gate Bridge OpeningFor more of my posts about commemorative coins and medals, including other Bay Bridge stories, see:
Commems Collection.