Pittsburg
Pittsburg, California, is a working class Bay Area suburb, about 30 miles northeast of Berkeley. Historically it has been dominated by the coal and steel industry, along with shipping and some fishing. The community's best days are behind it by 1973, as its industrial base cools off from its post-War high.
Frank DiGiuseppe lived in Pittsburg for much of his adolescent life, and then for a time after his return to the United States from Vietnam. He mailed one of his glyph-encoded threatening letters to Ed Dooley at the San Francisco Examiner from Pittsburg before returning to his flophouse apartment in San Francisco. His father, Armando DiGiuseppe, lived there until his death in February 1973.