American Association of Suicidology

The Carnegie Endowment for International Peace (CEIP) is a nonpartisan international affairs think tank headquartered in Washington D.C. Founded in 1910 by Andrew Carnegie, the organization describes itself as being dedicated to advancing cooperation between nations and promoting active international engagement by the United States. In the University of Pennsylvania's "2019 Global Go To Think Tanks Report", Carnegie was ranked the number 1 top think tank in the world. In the 2015 Global Go To Think Tanks Report, Carnegie was ranked the third most influential think tank in the world, after the Brookings Institution and Chatham House. It was ranked as the top Independent Think Tank in 2018.Its headquarters building, prominently located on the Embassy Row section of Massachusetts Avenue, was completed in 1989 on a design by architecture firm Smith, Hinchman & Grylls. It has also hosted the embassy of Papua New Guinea in the U.S. The chairperson of Carnegie's board of trustees is former U.S. Secretary of Commerce Penny Pritzker, and the organization's president is Mariano-Florentino Cuéllar, who replaced former U.S. Deputy Secretary of State William J. Burns.

The Brookings Institution, often stylized as simply Brookings, is an American research group founded in 1916. Located on Think Tank Row in Washington, D.C., the organization conducts research and education in the social sciences, primarily in economics (and tax policy), metropolitan policy, governance, foreign policy, global economy, and economic development. Its stated mission is to "provide innovative and practical recommendations that advance three broad goals: strengthen American democracy; foster the economic and social welfare, security and opportunity of all Americans; and secure a more open, safe, prosperous, and cooperative international system."Brookings has five research programs at its Washington campus: Economic Studies, Foreign Policy, Governance Studies, Global Economy and Development, and Metropolitan Policy. It also established and operates three international centers which are based in Doha, Qatar (Brookings Doha Center, and since 2021, the Middle East Council on Global Affairs or MECGA); Beijing, China (Brookings-Tsinghua Center for Public Policy, and since 2020, the Brookings-Tsinghua China Office at Tsinghua University); and New Delhi, India (Brookings India, and since 2020, the Centre for Social and Economic Progress or CSEP).The University of Pennsylvania's Global Go To Think Tank Index Report has named Brookings "Think Tank of the Year" and "Top Think Tank in the World" every year since 2008. The Economist describes Brookings as "perhaps America’s most prestigious think-tank."Brookings states that its staff "represent diverse points of view" and describes itself as nonpartisan, and various media outlets have alternately described Brookings as centrist, liberal, or right-wing. An academic analysis of congressional records from 1993 to 2002 found that Brookings was cited by conservative politicians almost as often as by liberal politicians, earning a score of 53 on a 1–100 scale, 100 representing the most liberal score. The same study found Brookings to be the most frequently cited think tank by U.S. media and politicians.

The Papua New Guinean ambassador in Washington, D. C. is the official representative of the Government in Port Moresby to the Government of the United States.

The American Enterprise Institute for Public Policy Research, known simply as the American Enterprise Institute (AEI), is a center-right Washington, D.C.–based think tank that researches government, politics, economics, and social welfare. AEI is an independent nonprofit organization supported primarily by contributions from foundations, corporations, and individuals. Founded in 1938, AEI is commonly associated with conservatism and neoconservatism but does not support political candidates. AEI advocates in favor of private enterprise, limited government, and democratic capitalism.AEI is governed by a 28-member Board of Trustees, composed of executives and former executives from various corporations. Approximately 185 authors are associated with AEI. Arthur C. Brooks served as president of AEI from January 2009 through July 1, 2019. He was succeeded by Robert Doar.

McCormick Apartments, also known as Andrew Mellon Building, Mellon Apartment, or 1785 Massachusetts Avenue Northwest, is a landmark apartment building on Embassy Row in Washington, D.C., whose inhabitants once included Andrew W. Mellon. It is the home of the American Enterprise Institute.

The Dupont Circle Fountain, formally known as the Rear Admiral Samuel Francis Dupont Memorial Fountain, is a fountain located in the center of Dupont Circle in Washington, D.C. It honors Rear Admiral Samuel Francis Du Pont, a prominent American naval officer and member of the Du Pont family. The fountain replaced a statue of Du Pont that was installed in 1884. Designed by Henry Bacon and sculpted by Daniel Chester French, the fountain was dedicated in 1921. Prominent guests at the dedication ceremony included First Lady Florence Harding, Secretary of War John W. Weeks and Secretary of the Navy Edwin Denby. The fountain is one of eighteen Civil War monuments collectively listed on the National Register of Historic Places in 1978. The marble fountain, which is adorned with three allegorical sculptures, rests on a concrete base and is surrounded by an open plaza. The fountain and surrounding park are owned and maintained by the National Park Service, a federal agency of the Interior Department.

The Peterson Institute for International Economics (PIIE), previously known as the Institute for International Economics (IIE), is an American think tank based in Washington, D.C. It was founded by C. Fred Bergsten in 1981 and is currently led by Adam S. Posen. The institute conducts research, provides policy recommendations, and publishes books and articles on a wide range of topics related to the US economy and international economics. According to the 2015 Global Go To Think Tank Index Report (Think Tanks and Civil Societies Program, University of Pennsylvania), PIIE was number 20 (of 150) in the "Top Think Tanks Worldwide" and number 13 (of 60) in the "Top Think Tanks in the United States".

The Embassy of Uzbekistan in Washington, D.C., (also known as the Clarence Moore House and the Old Canadian Embassy), is the diplomatic mission of the Republic of Uzbekistan to the United States. The current ambassador of Uzbekistan to the United States is Djavlon Vahabov. The embassy is located at 1746 Massachusetts Avenue NW on Embassy Row in Washington, D.C., between Scott Circle and Dupont Circle. Constructed in 1909, the Clarence Moore House is an example of Beaux Arts architecture in blond Roman brick with limestone dressings; it was used by the Canadian government until the 1980s. The house was listed on the National Register of Historic Places (NRHP) on April 3, 1973. The building is also designated a contributing property to the Massachusetts Avenue Historic District and Dupont Circle Historic District, which are both listed on the NRHP.

The Uzbek ambassador in Washington, D.C. is the official representative of the government in Tashkent to the government of the United States.

St. Thomas' Parish is an Episcopal church in Washington, D.C. It is part of the Diocese of Washington.

The Sulgrave Club is a private women's club located at 1801 Massachusetts Avenue NW on the east side of Dupont Circle in Washington, D.C. The clubhouse is the former Beaux-Arts mansion on Embassy Row built for Herbert and Martha Blow Wadsworth and designed by noted architect George Cary. During World War I the Wadsworth House was used as the local headquarters for the American Red Cross. In 1932 a group of local women led by Mabel Thorp Boardman established the Sulgrave Club and purchased the mansion. They chose architect Frederick H. Brooke to renovate the triangular-shaped building into a clubhouse. The Sulgrave Club was added to the District of Columbia Inventory of Historic Sites in 1964 and the National Register of Historic Places in 1972. The building is also a designated contributing property to the Dupont Circle Historic District and Massachusetts Avenue Historic District. The clubhouse is one of two remaining large houses on Dupont Circle, the other being the Patterson Mansion. The building was designed in the Beaux-Arts style, popular during the time of its construction. The clubhouse includes a lavishly decorated Beaux-Arts ballroom while some of the other rooms feature different architectural styles, including an Arts and Crafts entrance and Colonial Revival reception area.

The Chilean ambassador in Washington, D.C. is the official representative of the Government in Santiago de Chile to the Government of the United States.