Short answers, pulled from the story.
The Morgan Library & Museum is a museum and research library at 225 Madison Avenue in the Murray Hill neighborhood of Manhattan, New York City. It was completed in 1906 as the private library of banker J. P. Morgan and became a public institution in 1924.
The Morgan Library & Museum's collection contains more than 350,000 objects, including illuminated manuscripts, authors' original manuscripts, musical scores, drawings, photographs, maps, and rare books such as three Gutenberg Bibles.
Belle da Costa Greene was J. P. Morgan's personal librarian, hired around the time the library was completed. She remained in charge of the collection for more than four decades, overseeing acquisitions and cataloging, and stayed on after the library became a public institution in 1924 until her retirement in 1948.
The Pierpont Morgan Library was incorporated as a public institution in March 1924, when J. P. Morgan Jr. transferred the collection to a board of trustees with a $1.5 million endowment. However, it initially admitted only researchers; the general public was not allowed in until December 1942.
In 2024, museum staff discovered an unpublished waltz by Frédéric Chopin, dating from the 1830s, that had been held in the collection without being identified.
The 2006 expansion cost $106 million in total. Italian architect Renzo Piano designed it alongside preservation architect Beyer Blinder Belle. The project added underground galleries, an auditorium called Gilder Lehrman Hall, and a glass entrance building, and the institution was renamed the Morgan Library & Museum when it reopened on the 29th of April 2006.