Definitions, Methods, & Sources

The LifeCourse American Leadership Database consists of searchable records on nearly 14,000 U.S. political leaders.

Period Covered

The database covers U.S. office holders from the very first year in 1789 all the way to the present day. LifeCourse updates this database every two years, within six months of every biennial election to the U.S. Congress.

A separate page offers a generational breakdown of participants in major events and congresses during the revolutionary era. These include the colonial delegates to the Stamp Act Congress (1765), known members of the Boston Tea Party Riot (1773), signers of the Declaration of Independence (1776), signers of the U.S. Constitution (1787), revolutionary and state governors (1775 to 1787), delegates to the Continental Congress (1775 to 1787), and Presidents of the Continental Congress (1774 to 1789).


The database includes every holder of the following elected or appointive offices since 1789:

  • U.S. Presidents and Vice Presidents
  • U.S. Supreme Court Justices
  • House and Senate members of the U.S. Congress
  • U.S. State Governors

Dates in Office

The dates in office are grouped by U.S. congressional term or by the period of exactly two calendar years (odd number-even number) corresponding to that term.

For members of Congress, the results for each Congress include all representatives or all senators serving in the House or Senate (however briefly) during that entire two-year Congress. The results for the Senate for the 70th Congress (1927–1928), for example, refer to all senators who served at any time during that Congress, which convened on March 4, 1927 and adjourned on March 3, 1929.

Because of turnover (due to deaths, vacancies, impeachments, resignations, etc.), and because of missing data (e.g., when birth years are unknown), the total number of members listed for any single Congress often do not add up exactly to the total number of seats in that house, which today is 100 for the Senate and 435 for the House of Representatives. In recent decades, the member total is typically slightly larger than the seat total.

For the President and Vice President, the results for each Congress include all office holders during the Presidential term that corresponds to the two successive congressional terms. In case of death or resignation in any given calendar year, the term is deemed to end or begin during the Congress associated with that year.

For U.S. state governors and Supreme Court justices, the results for each Congress include all office holders at the calendar-year midpoint of that Congress. The results for governors in the 55th Congress (1887–1888), for example, includes all governors who were serving at midnight on December 31, 1887. This calculation method generally does ensure that total number of office holders for any single Congress exactly adds up to the total number of seats, which today is 50 for governors and 9 for justices. The only exception would be for leaders (mostly governors born in the 1700s) whose birth dates are unknown.

Primary Leader Attributes

The database record for each office holder contains the following nine fields: (1) first name, (2) last name, (3) date of birth, (4) office(s) held, (5) term starting date(s), (7) term ending date(s), (6) date of death, (7) political party, (9) state.

For some office holders, the date of birth is unknown. The number of records with missing birth dates is small; in no year do they comprise more than one percent of leaders serving. Since most of them were born before 1830, this absence hardly ever appears in terms of office after 1900. Also, some office holders have no political party, either because they didn’t belong to one or it is unknown.

The same individual may have more than one office held, or may occupy the same office, but change political party and/or state. A separate record is created when a person occupies the same office, but changes party or state. Such people may thus be “double-counted” in a search that encompasses multiple terms of office in which they switched party or state. A separate record is not created, however, for a person with multiple offices held (say, someone who was a governor and then a senator) or someone who simply enters the same office at different times without changing state or party.

For most offices, the state refers to the state or district officially represented by the office holder. For Presidents, Vice Presidents, and Supreme Court justices, it refers to the state of origin typically mentioned in official biographies.

Derived Attributes and Indicators

The database itself calculates several “derived” leader attributes or collective leadership indicators.

  • A region is a group of states, defined on the database in a pull-down menu. By using regions, database users can conveniently examine geographical differences at a broader-than-state level.
  • The average age is often calculated to indicate the average age of all leaders in one year or to indicate, during the lifetime of an entire cohort of leaders, the average age of their entry into leadership or of their death.
  • The longevity refers to the average age of death of any group other than a cohort group.
  • A generation refers to leaders born in a birth-year range corresponding to the generations of Americans defined in the published works of Howe and Strauss. For a full list of Howe-Strauss generational birth years, click here.
  • A leadership share is, for any position during a Congress or span of Congresses, the share of all leaders in that position belonging to a defined birth-year range.
  • A national leadership share is the unweighted average of the leadership shares, during a Congress or span of Congresses, of all senators, all representatives, and all governors.
  • A generational leadership share is, for any Congress or span of Congresses, the share of all leaders belonging to a generation as defined by Howe and Strauss.


For all members of both houses of the U.S. Congress (Senate and House), the leadership data are imported directly from the Biographical Directory of the United States Congress, 1774–Present, now published online through the joint efforts of the U.S. Senate Historical Office and Legislative Resource Center of the U.S. House of Representatives. This database, now continuously updated, used to be published in multi-volume hard-copy form. The first edition was published in 1859, under the title Biographical Directory of the United States Congress.

For all U.S. state governors, Presidents, Vice Presidents, and Supreme Court Justices, our data are compiled from Congressional Quarterly, American Political Leaders, 1789–2000 (or more recent editions). With U.S. governors, in questionable cases, recourse is sometimes made to official state websites or to Larry Kestenbaum’s valuable website,

For revolutionary-era leaders, including colonial governors and delegates to the Continental Congress, please see Appendix B (both tables and references) of Howe and Strauss, Generations (1991).


We are deeply indebted to Jim Graham, of Spark Media Group, whose creative and tireless work on the design and structure of the database made this entire site possible.