Question: Charles Douglas "Cully" Stimson joined an American conservative think tank based in what location?

full_context: Document 1: The Heritage Foundation: The Heritage Foundation (abbreviated to Heritage) is an American conservative think tank based in Washington, D.C. The foundation took a leading role in the conservative movement during the presidency of Ronald Reagan, whose policies were taken from Heritage's policy study "Mandate for Leadership". Heritage has since continued to have a significant influence in U.S. public policy making, and is considered to be one of the most influential conservative research organizations in the United States. After the 2016 election of Donald Trump as U.S. President, Heritage leader Rebekah Mercer played a major role in shaping his transition team.
Document 2: Charles Stimson: Charles Douglas "Cully" Stimson (born June 13, 1963) is an American lawyer and government official. Stimson served as the Deputy Assistant Secretary of Defense for Detainee Affairs from 2005 until his resignation on February 2, 2007, following a controversy about his statements on legal representation for prisoners at Guantánamo Bay. Following his time in the George W. Bush administration, Stimson joined The Heritage Foundation, where he is currently a senior legal fellow and manager of the National Security Law Program. Earlier in his career, Stimson served as an Assistant United States Attorney for the District of Columbia and as Vice President for Private Equity Mergers & Acquisitions at Marsh & McLennan Companies.
Document 3: Lee Edwards: Lee Edwards (born 1932 in Chicago, Illinois) is a distinguished fellow in conservative thought at the B. Kenneth Simon Center for American Studies at The Heritage Foundation. A historian of the conservative movement in America, and he has published more than 15 books, including biographies of President Ronald Reagan, Senator Barry Goldwater, Attorney General Edwin Meese III and William F. Buckley, Jr. He is currently the Chairman of the Victims of Communism Memorial Foundation.
Document 4: John Marshall Mitnick: John Marshall Mitnick is an American attorney who serves as Senior Vice President, General Counsel, and Secretary of the Heritage Foundation. He is President Donald Trump's nominee to become General Counsel of the United States Department of Homeland Security. Mitnick previously served as Vice President, General Counsel, and Secretary at Raytheon. During the presidency of George W. Bush, he served as Deputy Counsel of the Homeland Security Council and then as Associate Counsel to the President.
Document 5: The Daily Signal: The Daily Signal is an American political journalism news website founded in June 2014. The publication focuses on politics, policy, and culture and offers political commentary from a conservative perspective. It is published by conservative think tank The Heritage Foundation.
Document 6: Lee S. Wolosky: Lee Scott Wolosky (born July 17, 1968) is the former U.S. Special Envoy for Guantanamo Closure. He served under the last three U.S. Presidents in significant national security positions, and was on leave as a Partner at Boies, Schiller & Flexner LLP. On July 14 2016, President Obama accorded Wolosky the personal rank of Ambassador.
Document 7: Great America PAC: Great America PAC is a Super PAC that supported Donald Trump in the 2016 Presidential Election. It was founded in 2016 by Eric Beach, a political strategist who is a veteran of presidential campaigns. Beach soon brought on Ed Rollins, a long time Republican campaign consultant and strategist who served as the campaign manager for Ronald Reagan's 1984 presidential campaign.
Document 8: Thomas Fleener: Thomas Fleener is a military officer and lawyer. Fleener, a major in the United States Army Reserve, has been appointed to serve as a defense lawyer in the Guantanamo military commissions. He has been appointed to serve as the defense lawyer for Ali Hamza Ahmed Sulayman al Bahlul.
Document 9: Khalid al-Odah: Khalid al-Odah is the father of Guantanamo Bay detainee, Fawzi al-Odah, and the founder of the Kuwaiti Family Committee, a group established in 2004 to heighten global awareness of the prisoners in Guantanamo Bay. Over the past five years, Khalid has waged legal, media, and public relations campaigns to promote the need for due process for the prisoners at Guantanamo. In 2004, Khalid brought his son's case to the Supreme Court Rasul v. Bush/ al-Odah v. Bush.
Document 10: Rick Dearborn: Rick A. Dearborn is currently the White House Deputy Chief of Staff for Legislative, Intergovernmental Affairs and Implementation and formerly the executive director of Donald Trump's presidential transition team. Dearborn has worked for six U.S. Senators, including two members of Senate leadership, and spent more than 25 years working on Capitol Hill. He was nominated by President George W. Bush and confirmed by the Senate to become the Assistant Secretary of Energy for Congressional Affairs, where he worked with the Senate, House and Tribal Governments on achieving President George W. Bush's Energy Agenda. Rick Dearborn was a member of Donald Trump's presidential transition team, a group of advisors tasked with recommending presidential appointments for the incoming administration. Dearborn had previously worked as the Chief of Staff for Senator Jeff Sessions from December 2004 until 2016. Dearborn, along with Senior Advisor Stephen Miller, is one of two former senior Sessions staffers to have a senior role in Trump's White House.
Document 11: Robert Charrow: Robert Charrow is an American lawyer and government official. Currently a shareholder at the law firm of Greenberg Traurig, he is President Donald Trump's nominee to become General Counsel of the United States Department of Health and Human Services. He previously worked for the law firm of Crowell & Moring. In the Ronald Reagan administration, Charrow served as Deputy and then Principal Deputy General Counsel for the U.S. Department of Health and Human Services. In those roles, he supervised the chief counsel for the Health Care Financing Administration, Office of Inspector General, the Food and Drug Administration, and the United States Public Health Service.
Document 12: McCain Institute: The McCain Institute for International Leadership is a Washington, D.C.-based think tank in cooperation with Arizona State University whose mission is to "advance leadership based on security, economic opportunity, freedom, and human dignity, in the United States and around the world." The institute was formed in 2012 and is named after U.S. Senator and 2008 Republican Party presidential nominee John McCain from Arizona. Based in Washington, D.C., the McCain Institute is part of Arizona State University. The current executive director of the McCain Institute is Kurt Volker.
Document 13: Kirstjen Nielsen: Kirstjen M. Nielsen is a government official and national security expert who currently serves as Principal Deputy White House Chief of Staff to U.S. President Donald Trump since September 6, 2017. She informally performed the role of Deputy Chief of Staff since the time John F. Kelly became White House Chief of Staff on July 31, 2017. Nielsen had previously served as Kelly's Chief of Staff at the Department of Homeland Security. She is the founder and former President of Sunesis Consulting. Prior to serving in the Trump administration, she was a senior fellow and member of the Resilience Task Force of the Center for Cyber & Homeland Security think tank at the George Washington University and served on the Global Risks Report Advisory Board of the World Economic Forum. She holds degrees from the Georgetown School of Foreign Service and the University of Virginia Law School.
Document 14: Cato Institute: The Cato Institute is an American libertarian think tank headquartered in Washington, D.C. It was founded as the Charles Koch Foundation in 1974 by Ed Crane, Murray Rothbard, and Charles Koch, chairman of the board and chief executive officer of the conglomerate Koch Industries. In July 1976, the name was changed to the Cato Institute.
Document 15: Cheryl Mills: Cheryl D. Mills (born 1965) is an American lawyer and corporate executive. She first came into public prominence while serving as deputy White House Counsel for President Bill Clinton, whom she defended during his 1999 impeachment trial. She has worked for New York University as Senior Vice President, served as Senior Adviser and Counsel for Hillary Clinton's 2008 presidential campaign, and is considered a member of Hillary Clinton's group of core advisers, self-designated as "Hillaryland". She served as Counselor and Chief of Staff to Hillary Clinton during her whole tenure as United States Secretary of State. After leaving the State Department in January, 2013, she founded BlackIvy Group, which builds businesses in Africa.
ground_truth: Washington, D.C.