Hotel Pennsylvania, ca. 1919

Upon its opening in 1919, the Hotel Pennsylvania was the world's largest hotel, with 2,200 rooms on 22 floors. Designed by William Symmes Richardson of the firm of McKim, Mead & White, the hotel was one of the first to have private baths in every room. This was one of the many factors that made the hotel one of the most luxurious in the city at the time. Every detail was meticulously seen to, every feature of the hotel catered to the possible needs of the guests.

The hotel also debuted its signature "servidor." The door to each hotel room had a two-sided cabinet concealed within. This allowed the guest to place an order, and the hotel staff to fill the order without entering the room. This service was used for laundry, food, and mail delivery.

The building remains a hotel today, despite various threats of demolition between 1997 and 2010.