The mid 20th century was a time of suburban development, prosperity, and growth. Housing and schools mushroomed along the El Camino Real, west of the old town center. The town was still one of industry. Steel mills, meat packing plants, and paint factories continued their production, but the stockyards were used less and less.
South San Francisco as an "industrial city" began to change. Heavy industry slowly gave way to light industry and distributing firms using nearby San Francisco Airport to import their goods.Industrial Acres Business Park was built in 1953. Airport Industrial Park was completed in 1957. Utah Construction Co. built South San Francisco Industrial Park (1958-61) on former marshlands. Starlite and Lindenville Industrial Parks (1958) developed on the sites of wartime housing projects near South Linden and Spruce Avenues. Person, Swanson, and Bothin Industrial tracts (near Lowrie Avenue) were being planned in the late 1950s. By 1958 South San Francisco had 170 industrial plants. Stuart Manufacturing, Sun Tube Corp., Sees Candy, and Ray Winther Co. arrived during that decade. Anchor Drug, Poletti Realty, Plaza Furniture, Ben Franklin Store, and F.D. Minucciani all opened businesses on Grand Avenue.
Because of housing shortages for the families of returning war vets, large scale migration to California, and urban flight from the cities, suburban housing developments were built here in the late forties and fifties. Avalon Park (occupied 1954-55), Avalon Pines (1957-60), Buri Buri (1947-57), Country Club Manor (1956), Daly Subdivision (1951), Loma Linda Terrace (1956-57), Mayfair Village (1950-56), Park Avenue Heights (1956-57), Park Haven (1954-57), Parkway Terrace (1948-56), Pecks Heights (1955), Serra Highlands (1955-56), Sterling Manor (1950-51), Sterling Terrace (1949-51), Southwood (1950), Strawther (1952), Sunshine Gardens (1953-57), Viewmont Terrace (1957), Westview Terrace (1953-55), and Winston Manor (1951-54) were all developed during that period. Spruce Avenue was extended across former marshland to connect to El Camino Real.