collect material for his private library until his death in March 1913. His estate was valued at $128 million (about $ billion in ), over half of which lay in the worth of his collection. J. P. Morgan's will bequeathed the art collection to Jack, with the request that Jack make the collection "permanently available for the instruction and pleasure of the American people". The month after J. P. Morgan's death, the New York state legislature granted a two-year exemption enabling Jack to import his father's overseas collection without having to pay import duties. However, Jack Morgan sold off much of the overseas collection rather than importing it. During 1914, the collection was displayed in full at the Metropolitan Museum of Art, the only time the whole collection was displayed. The import duty exemption expired in April 1915, and Jack sold various items in the collection to pay the inheritance taxes and to raise money for the cash bequests in his father's will. The taxes were substantial, totaling $7.5 million in 1916. Frances Morgan, Jack's mother and John Pierpont's widow, continued to live at J. P. Morgan's old residence until her death in November 1924. Public institution and expansion Incorporation and mid-20th century Jack and Jane Morgan continued to employ da Costa Greene as the librarian, expanding the collection with items in which they were personally interested. In March 1924, the Pierpont Morgan Library was incorporated as a public institution. The Morgans transferred the library's building, and the land under J. P. and Frances Morgan's old residence at 219 Madison Avenue, to the Pierpont Morgan Library. The move came as, despite Jack's opposition, the surrounding stretch of Madison Avenue was being redeveloped as a business street. By 1927, the library was planning to double its area; the old J. P. Morgan residence was being demolished to make way for the annex. The plans called for an expanded two-story Italianate style structure designed by Benjamin Wistar Morris, with space for offices, exhibitions, and a research library. The annex, made of the same Tennessee marble as the original, was completed in 1928. While architectural historian Robert A. M. Stern said the addition "did not frame McKim's jewel box so much as sidle up to it like an unattractive sibling", Norval White and Elliot Willensky thought the annex "modestly defers to its master". Jack Morgan continued to live at 231 Madison Avenue until