A bit fuzzy, but a book found on my shelf:

A Field Guide to America's Historic Neighborhoods and Museum Houses: Western States, V. & L. McAlester, Alfred A Knopf, Inc ©1998, ISBN 0-679-42569-1 (hc) 0-375-70172-9 (pbk)

reports that most home construction in Sacramento from 1918 and for some time after was in the "East Sacramento" district, and the earlier houses there were mostly "Craftsman" or "Four-square" styles. Since these are simpler styles than what was popular in the earlier building periods (or simpler than what survived from those times) it might indicate a "working class boom" of some significance at about the begining of the 1920s. This is, of course, pure speculation, but might be suggestive enough to help with interpreting other more solid narratives you come across.

Many states and localities within them do have "Historical Societies" and there are often "Genealogical Societies" with lots of materials about the people in a particular area. (Some of these may have web sites that could be useful.) References at public libraries often don't have as much as might be expected of the kind of information you want, but the libraries should be able to steer you to a Historical or Genealogical group with more "pithy" references if they don't have sufficient information in their own holdings.

I'm not sure whether the time frame is quite right, but many places in the US produced "anniversary books" at 50th or 100th anniversaries of first settlements, city charters, etc.. Since these were often produced by local newspaper printers (only a few of which could really be called publishers) they're much more likely to have survived in small towns near the area of interest (local libraries or town museums) than in the larger depositories in "the big cities."

Since the railroad arrived only a little before the time range of interest, you might find significiant bits and pieces of local/regional history in railroad union newsletters, many of which are on the web although most of them may require a little more than "casual searching" to find. I'm not sure that shipyard unions were all that well organized by the time you want, but most such, if they existed, would have produced regular "newsletters" that might possibly be found online.

John