A British recruitment poster from 1915K.J. Historical/Corbis; David Pollack/Corbis; Swim Ink 2/Corbis; Heritage/Corbis; Corbis
After the United States entered the war, in April 1917, the government tried a high-minded plea for Americans to open their wallets.
A 1918 poster called on every American to pitch in.
An appeal to American manliness, to fill the ranks for an unpopular venture.
In the first six weeks after the U.S. declared war, only 73,000 men volunteered, prompting the govern- ment to institute a draft.
A 1917 Canadian poster. As a British dominion, Canada entered the Great War the moment Britain did.
The commander of the American Expeditionary Forces, John J. Pershing
In 1918, the Central Powers pleaded with their straitened citizens for yet another round of loans.
Great Britain recruits noncombatants.
Practical appeals to young American men in search of a trade
The YMCA owned 44 factories in Europe, which made cookies and candy for Allied troops.
In a 1918 poster, the strapped British government turned to women, who were barred from fighting, to fill noncombat positions.
The work of Britain’s Bert Thomas, a longtime contributor of political cartoons to the humor magazine Punch.
An appeal to Britons living abroad to come home to join their country at war
To finance victory, the U.S. government called on Americans to buy war bonds.
A canine plea to Americans
Bert Thomas, preying on British guilt

Editor’s note: The print version of this photo essay included a poster called "War Savings Are Warships," which was in fact created and distributed during World War II.

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