The Census Bureau's staff, with its demographers, geographers. statisticians, mathematicians, economists, computer specialists, and members of other professional fields, has long had an international reputation for expertise in factfinding. For over a century, Bureau personnel have been active in the International Statistical Institute, which develops modern census techniques (including sampling), and they assisted in establishing the Inter-American Statistical Institute in 1940.

Direct technical assistance to other countries in the area of statistics began in the late 1930's with the assignment of staff members to advise Uruguay (on vital statistics) and Panama (on Its 1940 population census). In 1946, the Bureau established a formal organization, now the International Statistical Programs Center (ISPC), to train Latin American statisticians for their various 1950 census programs. In the early 1950's, technical assistance and training were extended to developing countries elsewhere, sponsored by what is currently the U.S. Agency for International Development (AID). At about the same time, the Bureau established another unit to study demographic and economic trends in a number of foreign countries.

Toward the end of the 1960's, the development of an international data base began, so that AID and other program agencies could keep up to date on population growth and distribution around the world and understand the implications of demographic trends. In 1983, the Center for International Research (CIR) was created by combining the Foreign Demographic Analysis Division and the International Demographic Data Center. CIR does research and analysis on data produced by other countries. It issues most of the Census Bureau's international data products, while ISPC focuses on providing training and technical assistance.