1915 - The Franz Premier Electric Cleaner is advertised for $25. It weighs 9 pounds, an improvement over the 1913 Bissell Electric Suction Cleaner which weighed 33 pounds.
1915 - The taxicab makes its first appearance in American cities. Service costs a nickel and the popularity of cabs leads to the development of intercity bus lines.
1915 - The first transcontinental telephone line opens for service from New York City to San Francisco.
1915 - The first transatlantic radiotelephone communication is made from Arlington, Virginia to the Eiffel Tower in Paris.
1916 - Auto and truck production in the United States exceeds one million new vehicles this year. The average cost of a new car is slightly more than $600, but Ford's model T sells for $360. Half a million Model T's roll off the lines in 1916. There are more than 3.5 million cars on the road.
1916 - Trade both within the US and with foreign countries sets all-time highs. Domestic commerce generates $45 billion, and exports top $8 billion.
1916 - The self-service concept in retailing is invented by the Piggly Wiggly chain of grocery stores.
1916 - Boeing Aircraft Company designs and produces its first model, the biplane.
1916 - James Walter Thompson retires at 69 and sells his agency to Stanley B. Resor and partners.
1917 - A massive advertising campaign for Lucky Strike tobacco gets underway, employing the slogan "It's Toasted."
1917 - To support recruiting efforts and promote sales of war bonds and stamps during World War I, thousands of advertisers feature war themes in their campaigns while the media contribute space. By 1919, contributions total $2.5 billion.
1917 - The Liberty Loan Act is adopted. It provides for the public sale of bonds and the extension of loans to Allied Powers.
1917 - Maj. Gen. John J. "Blackjack" Pershing arrives in France with the first contingent of the American Expeditionary Forces (AEF) to enter the war in Europe.
1917 - The War Revenue Act establishes graduated personal income and excess profits taxes and higher postal rates.
1917 - The Trading with the Enemy Act establishes an office of Alien Property Custodian to handle enemy property in the US, most of which is sold. Trading with the enemy is prohibited, and all imports are placed under control of the War Trade Board.
1917 - The American Association of Advertising Agencies is formed.
1918 - The War Department buys the entire output of Bull Durham tobacco. The American Tobacco Company advertises, "When our boys light up, the Huns will light out."
1918 - A New York toy firm begins manufacturing the Raggedy Ann doll; the doll soon grows into a $20-million-a-year business.
1918 - The New York Times begins home delivery.
1918 - The War Finance Corporation is established to help banks finance the operation of war industries.
1918 - The National War Labor Board is established to settle labor disputes and avoid interruption of war production.
1918 - The first test kitchen in an ad agency is created in the Chicago office of the J. Walter Thompson Company.
1918 - The federal government takes control of the nation's telephone and telegraph systems.
1919 - The trade magazine Printer's Ink cautions against "an insidious campaign to create women smokers" in reaction to the portrayal of women in 'smart social settings' in cigarette ads. The first organized advertising campaign directed towards women would not come about until 1927; however, women were pictured in cigarette ads previous to this date.
1919 - George Whelan Tobacco Products acquires Phillip Morris & Company, Ltd. Inc. and its cigarette brands of Cambridge, Oxford Blues, English Ovals, Players, and Marlboro.
1919 - Manufactured cigarettes surpass smoking tobacco in poundage of tobacco consumed.
1919 - The Eighteenth Amendment to the Constitution is ratified, prohibiting the manufacture, sale, and transportation of intoxicating liquors.
1919 - To help stem rampant inflation, the administration of President Woodrow Wilson seizes and distributes food that had been stored in warehouses in several cities. Producers had stored the food as a way of keeping food prices high.
1919 - Since the passage of the child labor provision in the federal tax code in April, child labor is reduced by 40 percent, particularly in the coal mining and canning industries.
1919 - The nation's first municipal airport opens in Tucson, Arizona.
1920 - Drug, toilet, and household preparations output for domestic consumption is $765 million, up from only $40 million in 1879.
1920 - Almost 2 million passenger cars are sold in America.
1920 - The Nineteenth Amendment, giving women the right to vote, is ratified.