Q: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Tucson is commonly known as "The Old Pueblo". While the exact origin of this nickname is uncertain, it is commonly traced back to Mayor R. N. "Bob" Leatherwood. When rail service was established to the city on March 20, 1880, Leatherwood celebrated the fact by sending telegrams to various leaders, including the President of the United States and the Pope, announcing that the "ancient and honorable pueblo" of Tucson was now connected by rail to the outside world. The term became popular with newspaper writers who often abbreviated it as "A. and H. Pueblo". This in turn transformed into the current form of "The Old Pueblo".
A:
Who is thought to have led to calling Tucson 'The Old Pueblo'?