A new city charter effective in 1925 replaced the former "at large" voting system for a nine-member council with a district system with a 15-member council. Each district was to be approximately equal in population, based upon the voting in the previous gubernatorial election; thus redistricting was done every four years. (At present, redistricting is done every ten years, based upon the preceding U.S. census results.) The numbering system established in 1925 for City Council districts began with No. 1 in the north of the city, the San Fernando Valley, and ended with No. 15 in the south, the Harbor area.
As the city expanded to the north and west, the 4th District's boundaries likewise shifted in those directions.
1926: Wilshire District, with headquarters at 671 South Berendo Street (modern Koreatown).
1928: "With the exception that seven precincts are added to it in the territory bounded by Vermont Avenue and Hoover Street and Sunset Boulevard and Melrose Avenue, the lines . . . remain as Hoover street on the east, Western avenue on the west, Melrose avenue on the north and Washington street on the south."
1932–33: ". . . due to the exceptional growth of the western part of the city, a general movement toward the ocean was necessary." East boundary: Hoover. North: Melrose. West: Highland Avenue. South: Pico Boulevard or Wilshire.
1937: Bounded on the west by Crenshaw Boulevard, on the north by District 5 and Exposition Boulevard, on the east by the city boundary and on the south by Vernon Avenue.
1940: "The general trend is westward and northeastward, due to heavy construction in the San Fernando Valley and the beach areas." North: Santa Monica Boulevard or Melrose. East: Hoover. South: Wilshire.