For my interest in 1930's San Jose, the maps highlight the relative prosperity or exclusiveness of each neighborhood. The written description of each neighborhood also gives some background on the typical ethnic groups, issues with sewers or taxes, and expectations about whether the neighborhood was improving or going downhill fast.
To check out interactive Google maps with the grading overlays and the notes on each area, visit the Testbed for the Redlining Archives, and choose a California city from the menu in the upper left. Maps exist for San Francisco, Oakland, Stockton, San Jose, and other major cities, based on the 1937 records.
From a quick scan of the Oakland maps, I can see that East Oakland was in the third out of four categories. In the notes on the area, the banks noted that although the weather was nice and the Chevrolet Plant gave many jobs, there was an inharmonious mix of houses, a lack of shopping, a measurable number of the "Latin races" and an infiltration of the "Dark Portuguese". (I assume they're something like Dark Wizards.)
For San Jose, the south side of town (near the Barron Gray cannery) was labelled "Italian Town" and was firmly in the fourth, worst category, listing inhabitants as 75% Italian with infiltrations of Slavs, Portuguese, and Mexicans. Houses were typically 35 years old (ranging from new to 75 years old), in fair to dilapidated condition:
"The section is known as 'Italian Town' and is the slum section of San Jose. There are, however, many isolated blocks on secluded streets where the improvements and immediate surroundings would justify a 'B' or 'C' grading, but in every direction within a stone's throw of such spots will be found industries... The area as a whole contains many thrifty families and soundly improved properties, and applications for loans should not be rejected without investigation."
That "loans should not be rejected without investigation" exception wasn't true for all areas; the area close to the Del Monte cannery definitely fell in the "Loan Availability: None" category for an excess of immigrants and a reputation as a red light district.
The data on each neighborhood also describes typical sale prices at the peak in 1929, at the bottom in 1933, and at the time of the survey in 1937. It's easy to see that the Great Depression hit housing prices much like we've been hit in the last few years, with prices dropping 30% from the high, but recovering several years later.
Interesting data, especially for some very unvarnished descriptions of what neighborhoods were like in the 1930's. Check it out, and let me know if Faller starts making "Dark Portuguese" HO figures so I can put them around some of the houses near my canneries.
[Great thanks to Burrito Justice who mentioned the data on Twitter. He blogs some great stuff about San Francisco's history and Bernal Heights's got a great San Francisco (and Bernal Heights) current state. Great content, even if it is severely lacking in cannery-and-packing-house content, and if he shares more photos of Sutro Tower than of the Campbell Water Tower.]