was celebrated with exhibitions, symposia, concerts, lectures, the reopening of refurbished galleries, special tours, social events, and other programming for eighteen months from October 1969 through the spring of 1971. The centennial's events (including an open house, Centennial Ball, year-long art history course for the public, and various educational programming and traveling exhibitions) and publications drew on support from prominent New Yorkers, artists, writers, composers, interior designers, and art historians. 21st century In 2009 Michael Gross published The Secret History of the Moguls and the Money That Made the Metropolitan Museum, an unauthorized social history, and the museum bookstore declined to sell it. In 2012, following the earlier appointment of Daniel Brodsky as chairman of the board at the Met, the by-laws of the museum were formally amended to recognize the office of the chairman as having authority over the assignment and review of both the offices of president and director of the museum. The office of chairman was first introduced relatively late in the museum's history in the 1960s in contemplation of the anticipated donation of the Lehman collection to the museum and has since that time, under Brodsky, become the most senior administrative position at the museum. From 2016 to 2020, the museum operated a modern and contemporary art gallery at 945 Madison Avenue, a Marcel Breuer-designed building at Madison Avenue and 75th Street in Manhattan's Upper East Side, the former Whitney Museum of American Art. It extends the museum's modern and contemporary art program. In September 2018, it was announced that the Met intended to vacate the Met Breuer three years early, in 2020; the Frick Collection began occupying the space (still owned by the Met) while the main building underwent renovations. In January 2018, museum president Daniel Weiss announced that the century-old policy of free admission would be replaced by a $25 charge to out-of-state and foreign visitors, effective March 2018. The museum temporarily closed in March 2020 during the COVID-19 pandemic in New York City, and reopened in late August; this was the first time in over a century that the Met was closed for more than three consecutive days. In September 2020, the museum appointed Patricia Marroquin Norby (Purépecha/Nde descent) as the museum's inaugural Associate Curator of Native American Art. In May 2021, the museum installed a plaque on its Fifth Avenue facade in recognition of indigenous communities and of the fact that the