In 1925, Los Angeles passed the first ordinance establishing house numbering on all roads in the County. Owners and tenants were notified of the correct number of their address and were required to display that number or otherwise incur a steep fine. During the years that followed, the city exploded in size as it annexed assorted municipalities. In 1945, County engineers responded to a newly convoluted map by establishing a unified numbering system with City Hall at 1st and Main as its center point. Numbers originated there and increased as streets extended outward, dividing the city into four quadrants. That arrangement remains intact. If you are in the parking lot at Pink Elephant Liquors (1836 N. Western), you stand 18 blocks north of Beverly, the westward extension of 1st. If you are hustling through an alleyway behind 212 N. Avenue 53, you are two blocks north of Figueroa (the northward extension of Main), and 53 blocks above 1st. When it’s not hovering above Dodger Stadium, the Goodyear Blimp resides in its own airport in Gardena, at 19200 S. Main—exactly 192 blocks south of City Hall.

L.A.'s irregular geography and collage-like expansion defied the gridded logic of New York and Chicago, causing countless anomalies in the coordinate scheme. Streets unexpectedly change course or terminate. Independent cities like Santa Monica and Beverly Hills enforce numbering systems that frequently clash with the rules of the larger map.

Though it failed to impose perfect order on the natural chaos of Los Angeles County, the address system accidentally offered the contradictory metropolis its only unifying historical principle. Buildings are demolished, populations pass on, and neighborhoods mutate. The city changes. Addresses do not. Everything that happens, happens somewhere. Each resident shares his address with the invisible and the long departed. Even addresses with no history are full of it. Streets you have never seen still have names and numbers—in case, someday, you need them.

The city is vast and amorphous. This booklet is small and precise. It is not a walking tour, a visitor's guidebook, or a street atlas. It is a periodic index of lost heroes and miniature histories. Its only objective is to make the invisible equal to the visible.