It is one of 19 Smithsonian Institution museums and one of three Smithsonian facilities located in New York City, along with the National Museum of the American Indian's George Gustav Heye Center in Bowling Green and the Archives of American Art New York Research Center in the Flatiron District.

[2] Through the mid-20th century, the museum's collection came to include furniture, wallpapers, leatherwork, millinery, ceramics, jewelry, textiles, and media such as drawings and prints.

[2][13] As part of the agreement, the museum was to stay in New York City permanently and would remain in the Cooper Union's Foundation Building for three years.

[13] Even before it had finalized its acquisition, the Smithsonian was negotiating to lease the Andrew Carnegie Mansion on Manhattan's Upper East Side as the collection's new home.

[29] Lisa Taylor announced her retirement in 1987,[44][45] and the Cooper-Hewitt celebrated the tenth anniversary of its occupancy of the Carnegie Mansion shortly thereafter.

[60] The Carnegie Mansion's first-floor exhibit space reopened in September 1996,[61][62] Work on the passageway and design resources center continued through 1997,[61] and the renovation was not completed until 1998.

[68] Following the September 11 attacks, the Smithsonian ordered the Cooper-Hewitt to downsize, and Thompson eliminated four senior staff positions in June 2002, a move that prompted complaints from employees.

[70][72] News media reported in February 2005 that the Cooper-Hewitt was considering a $75 million proposal by Beyer Blinder Belle to expand the museum buildings.

[76] The Cooper-Hewitt hired Gluckman Mayner Architects to design the renovation,[76][77] along with Beyer Blinder Belle as preservation consultants.

[82][81] The Carnegie Mansion was closed to the public in July 2011, during which the museum held exhibitions at the headquarters of the United Nations[83] and on Governors Island.

[94][95] Renovations included an "Immersion Room", an interactive space that provides visitors digital access to the museums collection of wallpaper.

The main exhibition space was expanded and the museum had a custom open-source font, which remains available for free download and modification, designed for its reopening.

[97] The Cooper Hewitt hired conservator Cass Fino-Radin in 2016 to review the museum's digital collection, a process which took two years.

[98] Baumann resigned as director in February 2020, following an investigation by the Smithsonian's inspector general concerning her wedding[99][100] to John Stewart Malcolmson in 2018.

[106][107] These range from matchbooks to shopping bags, porcelain from the Soviet Union, and the papers of graphic designer Tibor Kalman.

[108][109] The museum holds the world's largest collection of works on paper by Hudson River School painter Frederic Edwin Church.

[110] By 1976, the museum's collection included 200 Tiepolo paintings, 2,000 F. E. Church sketches, and a large number of Winslow Homer drawings.

[6] When the museum acquired the Carnegie Mansion in 1972, it also received some interior decorations from the Widener family's townhouse at 5 East 70th Street (now the site of an annex to the Henry Clay Frick House).

[117] By the time the modern museum opened in 1976, it was recorded as having lantern brackets, window grilles, a balcony, 4,000 metal artifacts, and 30,000 international symbols donated by Henry Dreyfuss and his wife Doris.

[119][120] A punch bowl replicated by Eleanor Roosevelt, a scarlet Valentine Olivetti typewriter, and an Adrian Saxe vase were also part of the collection.

[141] When the Cooper-Hewitt showcased its own collections in 1992, it was the longest-running show in the museum's history at the time, lasting 17 months.

[148] Other exhibitions at the museum have included Puiforcat silver, wallpaper, the works of Alexander Girard, and universal design.

[151] In Cooper Hewitt's Face Values installation for the LONDON DESIGN BIENNALE 2018, a live facial data became the basis of dynamic graphic images and provocative conversations between humans and machines.

Curated by Ellen Lupton, the installation was awarded with the LONDON DESIGN BIENNALE EMOTIONAL STATED MEDAL WINNER 2018.

[153] Designed by Linked by Air, the platform allows users to explore objects one by one in thematic sequences, much they would wander around the physical galleries of an exhibition.

[155][156] In 2012, the Cooper Hewitt started work on its Harlem location, designed by Todd Oldham and sponsored by Target, which provided free workshops and programming.

[2] In 2006, the Cooper Hewitt and Mayor Michael Bloomberg declared October 15–21 National Design Week in New York City.

[170] When the Cooper-Hewitt moved into the Carnegie Mansion, a Newsday critic called the first exhibition "an unprecedented opportunity to see a museum as a mind-expanding playground".

[32] Both the Post and The Boston Globe wrote that the Cooper-Hewitt was similar in scale only to the Musée des Arts Décoratifs, Paris, and the Victoria and Albert Museum, London.

[32][118] A critic for Condé Nast Traveler wrote that the "Cooper Hewitt is worth a visit both for the collection and also for the building itself".