1920s: Innovations in Communication and Technology

By the end of this lesson, students will be able to:

• Account for how Henry Ford's moving assembly line, the five-dollar daily wage, and the Model T together built a mass market for the automobile in the United States during the 1910s and 1920s.
• Explain how household electrification, refrigerators, washing machines, and vacuum cleaners reshaped middle-class daily life in the 1920s.
• Account for the rise of commercial radio after the KDKA Pittsburgh broadcast of November 1920 and the founding of the National Broadcasting Company in 1926 and the Columbia Broadcasting System in 1927.
• Describe how the 1927 release of The Jazz Singer, the rise of Hollywood, and the cult of national sports celebrities (Babe Ruth, Jack Dempsey, Charles Lindbergh) produced a national rather than regional popular culture.
• Account for how mass advertising and installment-credit financing turned a manufacturing innovation into a national consumer market.
• Use Skill 5 (Causation) to argue how the technological innovations of Topic 7.7 produced the cultural conflicts of Topic 7.8 and the speculative boom that ended in the 1929 crash of Topic 7.9.

The 1920s did not invent the automobile, the electric grid, the radio, or the moving picture. Each had been around for at least a generation. What the 1920s did was bind the four together into a single consumer economy organized around mass production, mass advertising, and mass credit, and to do so on a scale that turned regional markets into a national market for the first time in American history. The College Board CED groups these innovations together under one topic because they reinforced one another: the automobile carried families to the movies, the radio sold the cars, the assembly line produced the radios, and the installment contract paid for everything. Topic 7.7 belongs to Theme WXT (Work, Exchange, and Technology) and is anchored by Key Concepts KC-7.1.I.A on new manufacturing and consumer goods and KC-7.2.I.A on the rising influence of popular culture and the debate over its effects on national values.

The hinge was the automobile. Henry Ford introduced the Model T at the Ford Motor Company in 1908, designed for durability on rough roads and built to a single specification ("any color so long as it is black") so that it could be priced for working families rather than the carriage trade. In 1913 Ford reorganized the Highland Park plant in Detroit around a moving assembly line, an idea borrowed in part from the meatpacking houses of Chicago, and cut the time required to assemble a Model T from more than twelve hours to roughly ninety minutes. In January 1914 Ford raised the daily wage at the plant to five dollars, more than double the prevailing factory rate, both to reduce the labor turnover that the new assembly line had produced and to put his own workforce within reach of the cars they were building. The price of a Model T fell from roughly $850 in 1908 to roughly $260 by 1925. By the end of the 1920s about half of American families owned an automobile (KC-7.1.I.A).

The automobile rebuilt the country in physical terms. Federal and state spending on paved roads rose sharply through the decade, the Bureau of Public Roads laid the network that would later become the U.S. highway system, and a new ring of automobile suburbs grew up around every major city, replacing the streetcar suburbs of a generation earlier. Daily commutes lengthened, vacation travel became a mass middle-class activity for the first time, and roadside businesses, gasoline stations, motor courts, and diners filled in the corridors between cities. The automobile also reshaped the lives it carried: the courtship habits of young Americans, the geography of the American family, and the meaning of leisure all changed because the family car could now go places the streetcar could not.

While Ford was building cars, the electric utility industry was wiring the cities. By 1930 roughly two-thirds of urban households had electric service, although rural electrification would have to wait for the New Deal's Rural Electrification Administration in 1935. Inside electrified homes, a wave of new appliances, the General Electric refrigerator, the Maytag washing machine, the Hoover vacuum cleaner, the electric iron, and the electric range, transformed domestic labor and produced the first generation of homes in which household work could be done in the evening without daylight or a coal stove. Manufacturers explicitly marketed the appliances at women, and women's magazines became the principal vehicle for the new mass-market advertising. The same electric grid that ran the appliances also ran the radio.

Radio was the breakthrough mass medium of the decade. On November 2, 1920, station KDKA in Pittsburgh, owned by Westinghouse Electric, received the first commercial broadcasting license issued by the federal government and went on the air with returns from the Harding versus Cox presidential election. KDKA proved that radio could carry news and entertainment to a paying audience in real time, and broadcasting expanded explosively in the years that followed. By 1922 there were roughly five hundred licensed stations in the United States; by 1930 there were roughly twelve million radio receivers in American homes, more than one for every three households. The National Broadcasting Company was founded in 1926, the Columbia Broadcasting System in 1927, and the radio network became the first nationwide medium capable of carrying a single program, a baseball game, a presidential address, a jazz performance, into living rooms from Maine to California simultaneously. Popular culture became national in a way it had never been before (KC-7.2.I.A).

Hollywood completed the picture. Silent film had been a mass entertainment since the nickelodeon boom of the early twentieth century, but the 1927 release of The Jazz Singer by Warner Brothers, the first feature-length picture to integrate synchronized dialogue and song, made the silent film obsolete almost overnight. By 1930 nearly all American films were sound films. Hollywood produced a national star system that ran in parallel with radio: Charlie Chaplin, Mary Pickford, and Rudolph Valentino were known by face and voice in cities and small towns alike. The same star machinery produced national sports celebrities such as Babe Ruth, who hit sixty home runs for the New York Yankees in 1927, the prizefighter Jack Dempsey, and, above all, Charles Lindbergh, whose solo nonstop flight from New York to Paris on May 20 and 21, 1927, in the Spirit of St. Louis was carried live on radio and produced one of the largest celebrity receptions in American history. Lindbergh's flight also demonstrated that long-distance air travel was a commercial as well as a heroic possibility, and the airline industry, including Pan American Airways, founded in 1927, and the network that would become the modern domestic carriers, took shape in the years that followed.

None of this would have produced a mass market without two parallel financial innovations: consumer credit and mass advertising. Installment buying, in which the consumer paid a small fraction of the purchase price as a deposit and the rest in monthly payments to a finance company, had existed before 1920, but it scaled in that decade to a degree that fundamentally restructured American household balance sheets. By 1927 roughly sixty percent of automobiles, eighty percent of radios, and three-quarters of major household appliances were purchased on installment credit, much of it carried by manufacturer-affiliated finance companies such as the General Motors Acceptance Corporation, founded in 1919. Mass advertising followed the credit. Total advertising spending in the United States roughly tripled between 1918 and 1929, magazines such as The Saturday Evening Post and Ladies' Home Journal built circulations measured in the millions, and a new profession of advertising men, headquartered on Madison Avenue in New York, refined the techniques (testimonial, fear appeal, lifestyle imagery) that would still define the industry a century later. Bruce Barton's 1925 best-seller The Man Nobody Knows, which presented Jesus of Nazareth as the founder of modern advertising, was the most-read book in the country (KC-7.2.I.A).

The consumer economy produced a set of demographic and political effects that the next two CED topics will develop in detail. A young consumer market emerged for the first time as a recognized commercial category, with its own music (jazz), its own clothing, and its own slang. The standard of living rose for the urban middle class, although unevenly: African American families, Mexican American families, recent immigrants, and rural Americans participated in the new consumer economy in much smaller proportions than middle-class urban whites, a disparity that would deepen during the Depression. The cultural confidence of the new urban majority of the 1920 Census produced the modernist side of the cultural conflict that Topic 7.8 will examine through Prohibition, the Scopes trial, the National Origins Act of 1924, and the revived Ku Klux Klan. The credit and equity boom that the new consumer economy produced created the speculative bubble in the New York stock market that broke on October 24, 1929, the subject of Topic 7.9. The consumer economy of the 1920s, in short, did not just describe the decade: it set the agenda for the twenty years that followed (Theme WXT; Reasoning: Causation).

Five primary sources, all in the public domain, anchor a Topic 7.7 lesson. Each is held by the Library of Congress or the Smithsonian and can be reproduced for classroom use. The set covers manufacturing, broadcasting, the talking picture, transatlantic aviation, and the new federal road network.

1. (Causation) Account for the chain of causes that connected the moving assembly line at Highland Park in 1913 to the mass-market automobile of the late 1920s. At which step in the chain did Henry Ford's January 1914 wage announcement matter most, and why?
2. (Continuity and Change) Compare American popular culture in 1915, when most entertainment was local and live, with American popular culture in 1929, when most entertainment was nationally produced and electronically delivered. Identify two continuities and two shifts.
3. (Causation) The KDKA broadcast of November 1920 produced an explosion of radio set ownership over the next ten years. Account for two reasons radio scaled so rapidly, and identify one social effect that became visible only after the audience reached a national scale.
4. (Comparison) Compare the cultural reach of The Jazz Singer in 1927 with the cultural reach of a typical silent film of the early 1920s. What did the addition of synchronized dialogue and music change about who watched movies and why?
5. (Causation) Account for how the parallel rise of installment credit and mass advertising in the 1920s contributed to the speculative climate that produced the October 1929 stock-market crash. Where would you place the most consequential causal step?

Draft alignment — pending educator review. AP USH codes correspond to the official College Board Course and Exam Description (Effective Fall 2023, Version 1). Statements below are paraphrased in the CountryReports voice; refer to the College Board's published CED for verbatim wording.