How many years did the Pony Express mail delivery service last?
The Pony Express was in operation for just around one-and-a-half years, from April 1860 to October 1861.
<START_INST>How many years did the Pony Express mail delivery service last?<END_INST><START_CTX><END_CTX><START_A>The Pony Express was in operation for just around one-and-a-half years, from April 1860 to October 1861.<END_A>