Walnut Park's residential build-up began in the 1890's with an influx of German Protestant families moving from the vicinity of Hyde Park. They moved from flats in the old section to single family dwellings in Walnut Park. A major portion of the area is residential, primarily single family homes built between 1900 and 1930. After 1900, Catholic groups of Croatians, Poles, Italians and Irish settled in the area, attracted by jobs in nearby industries.
In 1910, average sized lots (30 by 140 feet in size) could be had for $100 each and many of the houses built thereon were do-it-yourself projects. These were of frame construction; brick came into general use in the 1920's when two story houses with central heating became commonplace. About one-third of all housing in the area was built in that boom decade.
By this time, the population became predominantly Catholic with an increasing number of foreign born settling in the community. The depression caused unemployment and slowed down the housing construction; some development taking place in the section between Saloma and Bircher, west of Wren Avenue; World War II and the Small Arms Plant brought relative prosperity to Walnut Park in a period of sustained employment continuing into the 1960's.
The first blacks to move into the area arrived about 1963. Their influx was gradual but steady, and by late 1970, they represented at least one-half of the area population, with an even higher percentage at present.
Multiple dwelling units are widely scattered, with the exception of the section east of Union Boulevard, where four family flats prevail. In 1970, as previously, the incidence of homeownership in Walnut Park was rather high and neighborhoods had neat homes on tree-shaded streets.
Commercial activity in the early years saw a dominance of local business in the form of combination general stores and saloons, principally at intersections. Beginning about 1905, three major and two minor shopping districts emerged. These were on Lilian from Emerson to Thrush; on the south side of Florissant from Union to the streetcar loop at Robin and along Union north of Prange. Lesser activity located at Prange and Davison and along Thekla between Oriole and Robin. Later a sparse commercial strip developed along Riverview Boulevard. Eventual decline of local business in the area can be attributed to the changing age and economic patterns in the population and the increased mobility created by auto ownership and the consequent rise of regional shopping centers such as Northland and River Roads.
An industrial district is located in the eastern sector of the area, along the Terminal Railroad belt line. Among the plants located there are the Pillsbury Flour Mills (formerly Stanard-Tilton), Combustion Engineering Company, Alton Box Board Company and Barry-Wehmiller Machinery Company. Adjoining Walnut Park to the south, across Bircher, was the large industrial area which developed along the Terminal line early in this century. It included large industries such as the Chevrolet plant and the Pullman Company and was later augmented by the huge St. Louis Ordinance complex. This industrial area provided employment for Walnut Park residents and as it expanded, attracted newcomers to the area because of its proximity and employment opportunities. For many years, the Quality Dairy Company on West Florissant Avenue was an important economic force in the area. It was formed as a consolidation of several smaller neighborhood dairies about 1900. During the nineteenth century, much of the rural land in the area was occupied by dairy farms.
Shortly after the turn of the century, water mains and electric lines reached Walnut Park and by 1904, competition was rife between the Bell and Kinloch companies in providing telephone service. Laclede Gas began service to the area in 1905 for both domestic use and street illumination. Electric street lights were installed in 1929.