Scope and Content Correspondence re construction of Aliso St. Viaduct, much to Herbert C. Legg, WPA administrator, and Clayton E. Triggs, WPA administrator, from Lloyd Aldrich, City of LA engineer, re specifications for construction (1940)Receipts re construction of Aliso St. Viaduct, including insurance records (1940-1941) Correspondence re "improvement of the Los Angeles River channel by US Engineers" (1941) Correspondence and receipts re construction of Aliso St....