In 1914 , at the outbreak of World War I , American Express offices in Europe were among the few companies to honor the letters of credit ( issued by various banks ) held by Americans in Europe , because other financial institutions refused to assist these stranded travelers .
In 1914 , when World War I started , many people who happened to be traveling could not get at their money , but American Express offices in Europe were among the few companies to honor the letters of credit so that the American tourists could get money to travel back home .