My Four Years in Germany (1917), by James W. Gerard

American public opinion was generally against Germany from almost the beginning of World War I, but that didn't prevent the United States from having a diplomatic presence in Germany for the first 2 1/2 years of the war. This time period is described in My Four Years in Germany, by the American ambassador to Germany at the time, James W. Gerard (1867-1951).

Hurrah and Hallelujah (1917), by J.P. Bang

In the search for the causes of World War I, German society was often analyzed. Hurrah and Hallelujah: The Teaching of Germany's Poets, Prophets, Professors, and Preachers continued the discussion of German culture that earlier included the book The German Soul In Its Attitude Toward Ethics and Christianity, the State and War (1916), by Friedrich von Hügel.

The German Soul In Its Attitude Toward Ethics and Christianity, the State and War (1916), by Friedrich von Hügel

A discussion that began when World War I broke out—the influence of the German personality on the war—was continued in The German Soul In Its Attitude Towards Ethics and Christianity, The State and War. When the war started in August 1914, much attention was given to the 1911 book Germany and the Next War, by Frederick von Bernhardi.

The War and America (1914), by Hugo Münsterberg

The War and America was written during the first few weeks of the war, in the form of a diary.  An advertisement for the book in The New York Times on September 20, 2014 called it "The first authoritative work on the great European war."

The author was a German-born psychologist who lived in the United States.  Münsterberg was a prolific writer of books about psychology and sociology, in both German and English.  He also was a professor at Harvard when he wrote The War and America.