When Astor built the St. Regis in 1904, it overlooked Fifth Avenue's row of mansions and, at just 18 stories high, was the tallest skyscraper in the city.
It was modeled after the extravagant hotels of Europe that had not yet become ubiquitous in the US.
At that time, it was common for the very rich to live in luxurious hotels like the St. Regis for long stretches of time.
According to Nash, that hasn't changed, either: The hotel's presidential suite, which costs a cool $21,000 per night, is routinely occupied by the same guests for three months straight.
"They can walk around the hotel like it's their home, and nobody will disturb them," explained 25-year-old Jennifer Giacche, one of the hotel's butlers.
Image: Waiter Louis Rodopoulos, who has worked at New York's St. Regis Hotel for 56 years, walks through one of the hotel's kitchens on Wednesday, March 14, 2012.