Originally, in 1942, Frank Ayres & Son, developers were commissioned to create a healthy business district along Sepulveda in the new Westchester community.

The grand opening on March 17, 1949[2] was a "huge event that showcased the elegance and efficiency of postwar Modernism", according to the Los Angeles Conservancy.

[3] Millron's Westchester was considered strikingly innovative when it opened in 1949, in terms of both it attractive Late Moderne design and in being a suburban (but freestanding) department store, which was still relatively new.

[4] Although the building is not listed, the National Register of Historic Places registration form for Bullock's Pasadena references it and describes it as Late Moderne style, "a one-story department store, it also integrated parking lots into the plan, and added roof-top parking accessible via two criss-crossed ramps at the rear of the building.

Faced with unpainted brick, its facade displays regular bays marked by structural fins creating a flat-canopied loggia above the roofline.

An elevation wrapped around the secondary façade and screened a rooftop parking deck and stair towers from view at ground level and vertical concrete fins accentuated the apparent height, which from all main angles appeared to be that of a two-story building.