Mellon decided to use his fortune and art collection to establish a national art museum in Washington modeled after the National Gallery in London. In 1936, Mellon presented President Roosevelt with an offer to establish a national art museum to which Mellon would donate his art collection as well as an endowment, while the federal government would pay for the institution's upkeep. He conditioned the offer on the establishment of a board of trustees, a majority of whom would be chosen by Mellon. Despite the ongoing tax case against Mellon, the Roosevelt administration accepted the offer, and Congress passed legislation authorizing the construction of the National Gallery of Art on Mellon's terms. The National Gallery of Art opened in 1941 and continues to operate. Mellon's friend and former employee, David E. Finley Jr., would later preside over the establishment of the National Portrait Gallery, which also hosts several paintings donated by Mellon.