James Tannock Mackelvie intended that the residue of his estate be used to build a gallery in Auckland in which his collection would be displayed.
Since funds were insufficient to provide a new building, the trustees consented to the majority of the collection being exhibited in the Mackelvie Gallery of Auckland Art Gallery, added to the original building in 1893. The Mackelvie Collection grew considerably throughout the 20th century, including the purchasing of bronzes by Alexander Archipenko, Jacob Epstein, Henry Moore and more recently, Elizabeth Frink. Its most recent acquisition was a bequest of 30 watercolours depicting native flora by New Zealand artist Fanny Osborne (1852–1934). The decorative arts and book collections are now held by the Auckland War Memorial Museum and the Auckland Libraries.