Actually this bridge was not replaced in 1964. When the new parallel bridge opened in 1958, this bridge (causeway) was closed and modified. This span originally had a drawbridge. The drawbridge was removed and a high span approximating the newer parallel span was built over the intercoastal waterway.
It was reopened in 1964 as the Northbound span and the 1958 span was the new Southbound span.
https://galveston.newspaperarchive.com/galveston-tribune/196...
Brad, thanks for finding correct information, I've modified this entry to be for a long-demolished bridge and moved the postcard to the NB entry.