For Further Reading

More people in the U.S. cite German ancestry than any other nationality.  According to the 2015 Community Survey by the US Census Bureau, 46 million respondents identified as German, with the next highest (39 million) claiming African-American (non-Hispanic) ancestry, 35 million Mexican, 33 million Irish, and 25 million English, just to note the top five.  Of course, many respondents claimed mixed origins.    

For the full list and a comparison of 2000, 2015 and 2020 see: Ancestry of U.S. Population by Rank and

https://www.worldatlas.com/articles/largest-ethnic-groups-and-nationalities-in-the-united-states.html

German ancestry

For more information on the history and contributions of German immigrants in the US, see: GAHMUSA.ORG (German American Heritage Museum)

The Influenza Pandemic of 1918 killed over five times more people, globally and in the US, than died as combatants in “The Great War” (WWI). 

"It has been cited as the most devastating epidemic in recorded world history.  More people died of influenza in a single year than in four years of the Black Death Bubonic Plague from 1347-1351."


https://virus.stanford.edu/uda/

Although President Wilson and most of the American public wanted to remain neutral for almost three years of the war in Europe, the increasing toll of Germany's sinking US merchant ships, causing loss of American lives, led Wilson to call for "A War to End All Wars" and for the US to enter "The Great War".  Strong rhetoric, but in historical retrospect these views were tragically optimistic. Read more .:

https://www.rochester.edu/newscenter/looking-back-100-years-u-s-enters-world-war-i-on-april-6-1917/

Why did the US enter World War I?

Not many young men enlisted voluntarily as soon as the US entered the war, as Fred and Joannes did in the novel.  But men did serve when called up by the draft (70% of American soldiers during the war were conscripts). 

Source: Library of Congress Blog: The Draft in World War I: America “Volunteered its Mass”

https://blogs.loc.gov/headlinesandheroes/2018/06/wwi-draft/#:~:text=Wilson%20stressed%3A%20%E2%80%9DThe%20significance%20of,which%20has%20volunteered%20its%20mass.%E2%80%9D. :  

Military Conscription During WW1

Although not as widely researched as the pandemic's incidence in Philadelphia and Boston, the toll in Pittsburgh is believed to have been the highest of any major city for several reasons: the appalling state of the local environment and poor health of the population even before the disease struck;  the city's failure to apply sufficient quarantine measures, or to implement adequate relief measures; and the local government's premature lifting of the quarantine. See full article here.

Pittsburgh's unusually high mortality rate from the Spanish Flu

Source: Purple Death: When the 1918 flu pandemic came to Pittsburgh

See also: "Pittsburgh and the Influenza Epidemic of 1918-1919" Pennsylvania Magazine of History and Biography, Vol CXXXIV, No. 3 (July 2010)