SoonaftertheoutbreakofthesecondSino-JapaneseWarin1937,China'scoastandportcitieswereoccupiedbytheJapanese.ForwarmaterialstobesentbyothercountriestoChina,theonlyroutewasa717-miletrailbetweenKunmingandLashiointheBritishcolonyofBurma.
InresponsetoChiangKai-shek'scalltoturnthetrailintoahighway,200,000ChinesestartedworkingandtheBurmaRoadwascompletedin1938.Whattheylackedinequipment,theChinesemadeupforindetermination.OneAmericanengineerremarked,"MyGod,theyscratchedthethingoutofthemountainswiththeirfingernails!"
TheJapanesebegannear-dailybombingoftheroad."Letthemcome,"theChinesesaid."ItcoststheJapsathousanddollarseverytimetheydropabombontheroad.Evenwhentheyhitit,wecanfilluptheholesforonlyafewcents'worthoflabour."
一九三七年，第二次中日戰爭爆發，中國沿海地區和港市轉眼間落入日軍手上。中國要從外國輸入戰爭物資，只能靠一條七百一十七英里長的小徑。小徑一端接昆明，一端接英國殖民地緬甸的臘戌。
二十萬中國人響應蔣介石號召，着手把那小徑闢作大道。一九三八年，滇緬公路落成。中國人缺乏的是築路工具，但有的是毅力。美國一名工程師說：「老天，他們用手指甲，在重峯疊巒之間挖出這條公路！」
日軍開始轟炸滇緬公路，幾乎無日無之。中國人說：「讓他們來吧。日本鬼子向公路投一枚炸彈，就得花一千元；即使炸中了，我們填平炸彈洞，勞工費用不過幾分錢。」