At far right is Temple Square: the heart of the city at the turn of the last century. The street car is running on Main Street. The wide dirt road by the semi-circular postmark is Aliso Street, and the narrower road running parallel to it at right is Commercial Street.
Now, here's roughly the same east-northeast view a half-century later.
This photo was taken from the top of the present City Hall at the SW corner of Temple and Main (out of the picture to the right of where the street car is in the earlier view). Aliso Street has been replaced by the 101 freeway; Commercial Street runs just to the left of the large natural gas storage tower and to the right of the yellow Brew 102 brewery.
In the 1950s view, the street running from side to side in the lower center of the picture is Los Angeles Street. Two buildings on the east side of Los Angeles Street appear in both postcards. Can you spot which ones?
Here they are...
Buildings "A" and "B" on Los Angeles Street survived at least into the 1950s.
Neither structure still stands today, however.