▁Z imm ermann ▁gave ▁a ▁speech ▁in ▁the ▁Reich stag ▁in ▁which ▁he ▁admitted ▁the ▁tele gram ▁was ▁genu ine . ▁Z imm ermann ▁hoped ▁that ▁Americans ▁would ▁understand ▁that ▁the ▁idea ▁was ▁that ▁Germany ▁would ▁only ▁fund ▁Mexico ' s ▁war ▁with ▁the ▁United ▁States ▁in ▁the ▁prior ▁event ▁of ▁American ▁entry ▁into ▁World ▁War ▁I . ▁ ▁On ▁ 1 ▁February ▁ 1 9 1 7 , ▁Germany ▁began ▁un rest rict ed ▁sub marine ▁war fare ▁against ▁all ▁ships ▁in ▁the ▁Atlantic ▁bearing ▁the ▁American ▁flag , ▁both ▁passenger ▁and ▁merchant ▁ships . ▁ ▁Two ▁ships ▁were ▁s unk ▁in ▁February , ▁and ▁most ▁American ▁sh ipping ▁companies ▁held ▁their ▁ships ▁in ▁port . ▁Besides ▁the ▁highly ▁provoc ative ▁war ▁proposal ▁to ▁Mexico , ▁the ▁tele gram ▁also ▁mentioned ▁" r uth less ▁employ ment ▁of ▁our ▁sub mar ines ". ▁Public ▁opinion ▁demanded ▁action . ▁Wilson ▁had ▁previously ▁refused ▁to ▁assign ▁US ▁Navy ▁cre ws ▁and ▁guns ▁to ▁the ▁merchant ▁ships . ▁However , ▁once ▁the ▁Z imm ermann ▁note ▁was ▁public , ▁Wilson ▁called ▁for ▁ar ming ▁the ▁merchant ▁ships , ▁but ▁anti - war ▁elements ▁in ▁the ▁United ▁States ▁Senate ▁blocked ▁his ▁proposal . ▁ ▁On ▁ 6 ▁April ▁ 1 9 1 7 , ▁Congress ▁voted ▁to ▁declare ▁war ▁on ▁Germany ; ▁Wilson ▁had ▁asked ▁Congress ▁for ▁" a ▁war ▁to ▁end ▁all ▁wars " ▁that ▁would ▁" make ▁the ▁world ▁safe ▁for ▁dem ocracy ". ▁ ▁Wood row ▁Wilson ▁considered ▁another ▁military ▁invasion ▁of ▁Ver