- George Washington University - Ph.D. (History, 1972)
- Ohio State University - Ph.D. Candidate (History)
- University of Oklahoma - M.A. (Political Science)
- University of Oklahoma - B.A. (History)
- Distinguished Historian in Residence, American University, 1996 - 2012
- Adjunct Professor in History, American University, 1986-1988, 1992-1995
- Distinguished Visiting Professor in History, Arizona State University, January-June 1992
- Associate Professor in History, American University, 1991
- Adjunct Associate Professor in History, Tulane University, 1988-1990
- Professorial Lecture to Adjunct Associate Professor in History, George Washington University, 1970-1985
Consultant, Historical Division, Army Corps of Engineers, 1985-89
- Prepared a book length manuscript on the history of the Office of the Assistant Secretary of the Army/Civil Works. Book based upon research in federal records and manuscript collections as well as oral interviews.
Project Director, Committee on the Records of Government, July 1983-April 1985
- Chief investigator, administrator, and author with Committee Chairman Ernest R. May of the final report of a foundation funded study sponsored by ACLS, SSRC, and CLR. Creation of the Committee was prompted by a concern for the effect of technological changes (principally computers) on public records and archives.
Historical Consultant, National Academy of Public Administration Panel, "The Role of the president in managing the Federal Government," 1979-80
- Organized and coordinated research under direction of Hugh Heclo in four presidential libraries and the National Archives for a group of political scientists preparing issue papers for panel meetings, and books and articles for publication. Prepared chapter for publication on the president and the National Security Council, 1947-1961.
Consultant, Congressional Research Service (Foreign Affairs and National Defense), Library of Congress, September 1978 - January 1979
- Researched material in presidential libraries and private manuscript collections for a report on the role of Congress in the Vietnam War. Also conducted oral interviews with former members of Congress and former members of the Executive.
Research Associate, National Study Commission on Records and Documents of Federal Officials, June 1976-May 1977
- Initiated and prepared two studies for the Commission;a study of foreign policy records and papers, and a study of government historical offices and public records. Also prepared a study of the federal depository library program, assisted the director in conducting panels and public hearings and assisted in writing and editing the first and subsequent drafts of the Commission report.
Public Advisory Committees and Boards
- NSEP/Boren Scholarship Committee, American University, 2005, 2007.
- Council for International Exchange of Scholars, Discipline Advisory Committee in American History, 1995-1996.
- John F. Kennedy Assassination Records Review Board (Presidential Appointment, Senate Confirmation), 1994-1998. [Nelson article in February 1998 OAH Newsletter]
- Department of State Advisory Committee on Historical Diplomatic Documentation (Representing the Organization of American Historians), 1992-1994.
- Committee on Fulbright Applicants, Stone Center for Latin American Studies, Tulane University, 1989.
- Faculty, National Endowment for the Humanities Summer Seminar for College Teachers, 1984.
- Reviewer and/or Panel Participant, National Endowment of the Humanities, 1983, 1987, 1988, 1990, 1991, 1997.
- Advisory Committee on Records, American Institute of Physics, 1978-80.
Service to Professional Organizations
American Historical Association Joint Committee of Historians and Archivists, 1989-91
- Member (elected), Research Division, 1986-88
- Congressional Fellowship Committee, 1984
Commission on Preservation and Access
- Scholarly Advisory Committee on History, 1989-1990
National Council of Public History
- Editorial Board, The Public Historian, 1991-1993
- Chair, Publications Committee, 1985-89
- Executive Committee, 1984-1986
Organization of American Historians
- Member, Richard Leopold Prize Committee, 2003
- Committee on Access, 1982-1988
- Joint Committee of Historians and Archivists, 1982-1984, (Chair, 1983)
- Frederick Jackson Turner Prize Committee, 1980
Policy Board, National Coalition for History, 2003-2012
Society for Historians of American Foreign Relations
- Council (elected) 2005-2007
- Nominating Committee (elected), 1995-98 (Chair, 1998)
- Editorial Board, Diplomatic History, 1991-1993
- Committee on Documentation, 1989-91
Society for History in the Federal Government
- Nomination Committee, 2003
- Executive Committee, 1980, 1993-96
Grants and Honors
- Troyer Steele Anderson Prize for Advancement of the Purposes of the American Historical Association, 2009.
- Public Policy Fellow, Woodrow Wilson Center, May-August 2007.
- Lyndon B. Johnson Library Research Grant, 2006.
- Lyndon B. Johnson Foundation Research Grant, 2003.
- Coalition on Government Information, the 1999 James Madison Award to the JFK Assassination Records Review Board. [American Library Association listing of recipients, 25 February 1999.]
- Society for History in the Federal Government, Franklin Delano Roosevelt Prize, 1988, for the Advancement of Historical Study of the Federal Government.
- Harry S. Truman Library Institute, Research Grant, 1987.
- American Historical Association, Beveridge Grant, 1985.