A question on occupation was included in every decennial census from 1850 to 2000, although information on occupation was not collected for the slave population in 1850 and 1860.
In general, a person’s occupation is the type of work that he or she does for pay, or in some cases as an unpaid family worker. Accurately describing someone’s occupation in a single word or in a few words is not always easy, and as a result, classifying reports of occupation accurately and systematically can be extremely difficult. Census data on occupation have been extremely inconsistent over time. For example, the number of detailed occupations shown in census reports was 323 in 1850, 584 in 1860, 338 in 1870, 265 in 1880, 218 in 1890, and 303 in 1900, as shown in U.S. Census Office (1904), Occupations. Starting in 1870, data on occupations were grouped into four or five major groups, which corresponded roughly to industrial sectors of the economy. In 1900, these were agricultural pursuits, professional service, domestic and personal service, trade and transportation, and manufacturing and mechanical pursuits. The 1910 census was the first to collect data on both occupation and industry, where industry refers generally to the primary business of the person’s employer. The classification of occupations became more systematic with more hierarchy during the 20th century. In the 2000 census, for example, the classification system included 509 detailed occupational categories, which could be collapsed into as few as 6 major occupational groups: management and professional; service; sales and office; farming, fishing and forestry; construction, extraction, and maintenance; and production, transportation, and material moving.
Figures 16-1 and 16-2 present consistent estimates of the occupational distribution for the United States from 1860 to 1990, as developed by Matthew Sobek (2006), “Occupations” in Historical Statistics of the United States: Millennial Edition,” Vol. 2, pp. 2-35 to 2-40 and pp. 2-133 to 2-139. These estimates are for 12 occupational groups, reflect the 1950 census classification system, and are based on the Integrated Public Use Microdata Series (IPUMS). (See Minnesota Population Center, no date, “IPUMS-USA, Frequently Asked Questions (FAQ)”) Figure 16-3 and Figure 16-4 present occupational data as published in census volumes. Figure 16-3 shows data for the United States for 1990, 2000, and 2010, which are not totally comparable due to changes occupational classification. Figure 16-4 shows data for the United States by region for 1940, 1970, 2000, and 2010, which are not totally comparable over time, but which permit a comparison of occupational distributions by region in each year.