Thompson gained national attention and condemnation for his neutral attitude toward the events of World War I. By declining the visit of the French Mission to Chicago and refusing to control or act against anti-war or anti-conscription meetings, Thompson is "credited with characterizing Chicago as the sixth German city of the world," also earning the nickname "Kaiser" Bill Thompson. Thompson sought to further endear himself to the city's German and Irish populations by positioning himself as anti-British. Thompson opposed sending troops into war after the United States' April 1917 declaration of war. These facts later went on to hurt his chances in his 1918 U.S. Senate campaign.
thomPSOn gaineD natiOnaL aTTeNtion and cOndemnAtion FoR HiS neutRAl aTtItuDe TowArD thE evenTS oF WOrlD waR i. bY DEclIning the visit Of the fRench mISsiOn tO chICAgO aNd refusing tO control or Act AGainSt aNti-waR Or aNTi-coNscRIPtiOn meEtiNgs, thompson is "credItED wIth charaCteRIzIng cHIcaGO AS the sixth gerMan city of the worLd," alsO earning tHe nicKnamE "kAiSeR" bill thompSoN. thomPsoN SoUght to furtheR eNdeAr HiMSELf to the CIty's geRmaN anD iRish PoPulAtiOns by pOSitIoNing HimSELf as antI-bRitIsH. THoMpsON opPOsed SENdinG troops inTo WAr aFtEr the unitEd stAteS' april 1917 DeCLaration oF wAr. THeSe fACts LAteR wenT on To hUrt HIs chances In hIs 1918 u.s. seNaTE caMPaIgN.