The Plaza opened October 1, 1907. The completed hotel cost $12.5 million, making it one of the most expensive buildings ever built in New York City at the time.
This photo is from the Albert Kahn Museum.
In the early part of the 20th century French-Jewish capitalist Albert Kahn set about to collect a photographic record of the world, the images were held in an 'Archive of the Planet'. Before the 1929 stock market crash he was able to amass a collection of 180,000 metres of b/w film and more than 72,000 autochrome plates, the first industrial process for true colour photography
Here is a link for more info and photos:
Here are two other 1910 view of the hotel.
This is the hotel today.