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.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: How many years did the Pony Express mail delivery service last?
### Input: 
### Response: The Pony Express was in operation for just around one-and-a-half years, from April 1860 to October 1861.