I just love this old "business district" postcard shot:
It shows a lot of the old West End, and a lot of the old city fabric wiped away by redevelopment and changes in transportation. Sacramento's waterfront was heavily industrial, with everything from grain mills to canneries to lumber mills to ironwork, and three different railroads running alongside the river.
If you note the building on M Street just past the Tower Bridge (which identifies this shot as post-1935) to the right, you'll notice it has a "slice" taken out of it. This is because the Sacramento Northern tracks off the bridge used to swing to the right between Front and Second Street into the SN's original freight station. This station was destroyed in a fire, and the brick freight station (visible in the photo just above that building with the slice) received cars via a sharp S-curve of track at Second and N Street (you can see the boxcars in front of the station.) The building was abandoned in favor of the Western Pacific freight station on Second and R Street after SN switched from electrics to diesel in the early 1950s.
The other artifact of the SN era in this photo is the old passenger station on Terminal Way. Find City Hall on the far left of the photo (should be easy to see if you can find the Cal-Western building, aka The Citizen Hotel) and it's the brick-red structure just up and to the right.
The big boat in the foreground is either the Delta King or the Delta Queen. They alternated between Sacramento and San Francisco, passing each other in the middle of the night somewhere on the Delta, from their construction in 1926 until they were taken out of service in 1940, so obviously this shot has to be from somewhere between 1935-1940.