Statue of Joseph Henry

The Smithsonian Institution ( smith-SOH-nee-ən), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded on August 10, 1846, it operates as a trust instrumentality and is not formally a part of any of the three branches of the federal government. The institution is named after its founding donor, British scientist James Smithson. It was originally organized as the United States National Museum, but that name ceased to exist administratively in 1967.Called "the nation's attic" for its eclectic holdings of 154 million items, the institution's 19 museums, 21 libraries, nine research centers, and zoo include historical and architectural landmarks, mostly located in the District of Columbia. Additional facilities are located in Maryland, New York, and Virginia. More than 200 institutions and museums in 45 states, Puerto Rico, and Panama are Smithsonian Affiliates. Institution publications include Smithsonian and Air & Space magazines. The institution's 30 million annual visitors are admitted without charge. Its annual budget is around $1.25 billion, with two-thirds coming from annual federal appropriations. Other funding comes from the institution's endowment, private and corporate contributions, membership dues, and earned retail, concession, and licensing revenue. As of 2021, the institution's endowment had a total value of about $5.4 billion.

The Smithsonian Institution Building, located near the National Mall in Washington, D.C. behind the National Museum of African Art and the Sackler Gallery, houses the Smithsonian Institution's administrative offices and information center. The building is constructed of Seneca red sandstone in the Norman Revival style (a 12th-century combination of late Romanesque and early Gothic motifs; built in the Gothic and Romanesque revival styles) and is nicknamed the Castle. It was completed in 1855 and designated a National Historic Landmark in 1965.

The Andrew Jackson Downing Urn, also known as the Downing Urn, is a memorial and public artwork located in the Enid A. Haupt Garden of the Smithsonian Institution on the National Mall in Washington, D.C.The outdoor sculpture of a garden vase−urn commemorates Andrew Jackson Downing (1815–1852), an American landscape designer and horticulturalist, and considered to be one of the founders of American landscape architecture. Shortly before dying at the age of 37, Downing developed a landscape plan for the National Mall that the United States government partially implemented until replacing it with the McMillan Plan of 1902 (see History of the National Mall).

The S. Dillon Ripley Center, better known simply as the Ripley Center, is one of the buildings of the Smithsonian Institution series of museums located in the National Mall in Washington, D.C. The above-ground portion is only a small pagoda, and it descends into a larger underground portion. The Ripley Center houses the International Gallery, The Smithsonian Associates, and the offices of the Smithsonian Contributing Membership. It contains a conference center, an art gallery, and meeting/class rooms as well as exhibition space. It connects underground to the Arthur M. Sackler Gallery, the National Museum of African Art, and the Freer Gallery of Art. The Smithsonian Associates was formed in 1992 from combining the Resident Associates Program with the Smithsonian National Associate Program. The Smithsonian Associates was established as the cultural, educational, and membership division of the Smithsonian Institution. These membership and educational programs include the Young Benefactors, Smithsonian Sleepovers, Resident Associates Program, Discovery Theatre, Regional Events, and the Art Collectors Program.The Art Collectors Program is devoted to the creation and appreciation of contemporary American limited-edition art and to creating a context for collecting and a forum for artists to discuss their work. The Program sells Smithsonian-commissioned contemporary fine art prints and posters by acclaimed American artists like Sam Gilliam and April Gornik. Its limited-edition prints are numbered and signed and come with a Certificate of Authenticity from the Smithsonian.

The Enid A. Haupt Garden is a 4.2 acre public garden in the Smithsonian complex, adjacent to the Smithsonian Institution Building (the "Castle") on the National Mall in Washington, D.C. It was designed to be a modern representation of American Victorian gardens as they appeared in the mid to late 19th century. It replaced an existing Victorian Garden which had been built to celebrate the nation's Bicentennial in 1976.

The Arthur M. Sackler Gallery is an art museum of the Smithsonian Institution in Washington, D.C., focusing on Asian art. The Sackler Gallery and the Freer Gallery of Art together form the National Museum of Asian Art in the United States. The Freer and Sackler galleries house the largest Asian art research library in the country. Founded in 1982, the Gallery is named after Arthur M. Sackler, who donated approximately 1,000 objects and $4 million to the building of the museum. Located on the south side of the National Mall, and being physically connected to the Freer Gallery of Art, 96% of the museum is located underground below the Enid A. Haupt Garden. Their donations and contributions have been protested by people who accuse them of being a key contributor to the opioid epidemic in the United States.

The National Museum of African Art is the Smithsonian Institution's African art museum, located on the National Mall of the United States capital. Its collections include 9,000 works of traditional and contemporary African art from both Sub-Saharan and North Africa, 300,000 photographs, and 50,000 library volumes. It was the first institution dedicated to African art in the United States and remains the largest collection. The Washington Post called the museum a mainstay in the international art world and the main venue for contemporary African art in the United States. The museum was founded in 1964 by a Foreign Service in Capitol Hill. The collection focused on traditional African art and an educational mission to teach black cultural heritage. To ensure the museum's longevity, the founder lobbied the national legislature to adopt the museum under the Smithsonian's auspices. It joined the Smithsonian in 1979 and became the National Museum of African Art two years later. A new, primarily underground museum building was completed in 1987, just off the National Mall and adjacent to other Smithsonian museums. It is among the Smithsonian's smallest museums. The African art museum took a scholarly direction over the next twenty years, with less social programming. It collected traditional and contemporary works of historical importance. Exhibitions include both internal and borrowed works and have ranged from solo artists to broad survey shows. The museum hosts two to three temporary exhibitions and ten special events annually. The preferred abbreviation for its name is NMAfA.

The National Museum of Asian Art consists of the Smithsonian Institution’s two Asian art galleries, the Freer Gallery of Art and the Arthur M. Sackler Gallery, which are situated in connecting buildings on the National Mall in Washington, D.C. The galleries are operated by the same board of trustees and share a budget. Both institutions are run by the same management, curatorial and other staff. The two galleries feature 45,000 works of Asian art.The Freer Gallery of Art opened in 1923 to display the nineteenth century American painting and Asian art collection of American industrialist Charles Lang Freer. Freer provided an initial endowment used to construct the gallery building. The Arthur M. Sackler Gallery was built next door to the Freer in 1987, after Arthur M. Sackler donated 1,000 objects of ancient Chinese art and $4 million for a museum to house them. The museums have separate collections. Based on Charles Freer's will, the Freer gallery can exhibit only works in its collection, and those works are not allowed to travel. The Sackler gallery can accept loaned objects and can also loan pieces from its collection.The museum is working to strengthen its connections with Korea and art institutions there.The museum ended cooperation with the Hong Kong Economic and Trade Office in 2022.In February, 2023, the museum entered into an agreement with the government of Yemen to hold and preserve 77 works of art that had been looted from that country. The items will be returned to Yemen when the civil war there ends. Among the works are 65 carved stone funerary stelae, which are approximately 2,500 years old.

The Freer Gallery of Art is an art museum of the Smithsonian Institution in Washington, D.C. focusing on Asian art. The Freer and the Arthur M. Sackler Gallery together form the National Museum of Asian Art in the United States. The Freer and Sackler galleries house the largest Asian art research library in the country and contain art from East Asia, South Asia, Southeast Asia, the Islamic world, the ancient Near East, and ancient Egypt, as well as a significant collection of American art. The gallery is located on the south side of the National Mall in Washington, D.C., contiguous with the Sackler Gallery. The museum is open 364 days a year (being closed on Christmas), and is administered by a single staff with the Sackler Gallery. The galleries were among the most visited art museums in the world. The Freer houses over 26,000 objects spanning 6,000 years of history from the Neolithic to modern eras. The collections include ancient Egyptian stone sculpture and wooden objects, ancient Near Eastern ceramics and metalware, Chinese paintings and ceramics, Korean pottery and porcelain, Japanese folding screens, Persian manuscripts, and Buddhist sculpture. In addition to Asian art, the Freer also contains the famous Harmony in Blue and Gold: The Peacock Room (better known as The Peacock Room) by American artist James McNeill Whistler which serves as the centerpiece to the Freer's American art collection. The museum offers free tours to the public and presents a full schedule events for the public including films, lectures, symposia, concerts, performances, and discussions. Over 11,000 objects from the Freer|Sackler collections are fully searchable and available online. The Freer was also featured in the Google Art Project, which offers online viewers close-up views of selected items from the Freer.

The DeYoung Red Diamond is a 5.03-carat unmounted rare red diamond. It is the third-largest red diamond in the world, and the only one on public display. Sydney DeYoung (for whom the diamond is named) obtained the diamond, which was mistaken for a garnet, at a flea market. The diamond was given to the Smithsonian Institution after DeYoung's death in 1986.

The Arts and Industries Building is the second oldest (after The Castle) of the Smithsonian museums on the National Mall in Washington, D.C. Initially named the National Museum, it was built to provide the Smithsonian with its first proper facility for public display of its growing collections. The building, designed by architects Adolf Cluss and Paul Schulze, opened in 1881, hosting an inaugural ball for President James A. Garfield. It was designated a National Historic Landmark in 1971. After being closed since 2004, the building reopened in 2021 with a special exhibition, Futures, scheduled to run through July 2022.

The Hope Diamond is a 45.52 carats (9.104 g; 0.3211 oz) diamond extracted in the 17th century from the Kollur Mine in Guntur, India. It is blue in color due to trace amounts of boron. Its exceptional size has revealed new information about the formation of diamonds.The stone is one of the Golconda diamonds. The earliest records of the diamond show that French gem merchant Jean-Baptiste Tavernier purchased it in 1666 as the Tavernier Blue. The stone was cut and renamed the French Blue (Le bleu de France); Tavernier sold the stone to King Louis XIV of France in 1668. It was stolen in 1792 and re-cut with the largest section of the diamond appearing under the Hope name in an 1839 gem catalogue from the Hope banking family. The diamond has had several owners, including Washington socialite Evalyn Walsh McLean, who was often seen wearing it. New York gem merchant Harry Winston purchased the diamond in 1949, touring it for several years before donating it in 1958 to the Smithsonian National Museum of Natural History in the United States, where it is on permanent exhibition.