The Mongols had one of the very first pony express systems for sending mail.

蒙古人拥有最早的用于发送邮件的小马快递系统之一。

It required twenty-five days for a passenger to make the overland journey to California by the stagecoach system, established in 1858, and more than ten days for the swift pony express, organized in 1860, to carry a letter to San Francisco.

乘坐 1858 年建立的驿马车系统，一名乘客需要 25 天的陆路旅程才能到达加利福尼亚，而 1860 年组织的快马快车则需要 10 多天才能将一封信送到旧金山。