According to the Moltke revisions of the Schlieffen Plan, the First Army was part of the strong right wing and positioned on the outer western edge of the German advance through Belgium and France.

By this time, the aggressive Kluck had advanced his First Army well south of von Bülow's position to 13 miles north of Paris.

The French learned of Kluck's change in course on September 3 thanks to reports from Allied aircraft, and this was independently confirmed by radio intercepts.

A surprise attack on 8 September by Franchet D'Esperey's (who had replaced Lanrezac) Fifth Army against Bülow's Second widened the gap which the British Expeditionary Force marched to exploit.

In fact the BEF was already over the Marne and Quast's attack against Maunoury's Sixth Army had failed, and suggests that this may be why Kluck avoided meeting Hentsch directly.

[7] Toward the end of March 1915, while inspecting an advanced portion of his troops, he was struck by shrapnel, which caused seven wounds and seriously injured his leg.

[4] General von Kluck wrote of his participation in the War in the volume entitled Führung und Taten der Erste (1920).

Kluck was mentioned in a bawdy British army song (whose lyrics were written to the tune of the traditional folk-song The Girl I Left Behind Me), which in the original ran: It was later reported styled in censored form, that is, in less offensive but wholly inaccurate language from a historical point of view.

Kluck is mentioned in Episode 2, “The Little Pink Book / Field Trip,” of Season 1 of the American animated comedy television series, Hey Arnold!