This report provides information on fields of bachelor's degrees in the United States using data from the 2009 American Community Survey (ACS). It includes estimates of fields of bachelor's degree by demographic characteristics including age, sex, race, Hispanic origin, nativity, and educational attainment. This report also looks at geographic and earnings differences across fields of degree. The ACS provided data on field of bachelor's degree for the first time in 2009. Respondents who held a bachelor's degree or above were asked to write in the specific field(s) of any bachelor's degrees earned (Figure 1). The U.S. Census Bureau coded these responses into 188 majors. These 188 majors were then collapsed into two overlapping sets of fields: one broad set containing five distinct fields and one detailed set with fifteen distinct fields. The broad set of fields includes: science and engineering; science- and engineering-related; business; education; and arts, humanities, and other. The detailed set of fields retains three of the five broad sets of fields: science- and engineering-related, business, and education. The detailed set of fields also breaks down the two broad fields of science and engineering and arts, humanities, and other into smaller fields. The organization of the detailed fields of degree relative to the broad fields of degree can be seen in the chart titled "Organization of Field of Degree Groups." This chart also includes examples of common majors within these fields. A full list of the 188 individual majors and their grouping into fields can be found in Appendix A. Highlights of the report include: (1) Of the 56 million people aged 25 and over with a bachelor's degree, nearly 20 million of them held a degree in a science and engineering field; (2) Men held 87 percent of the degrees in engineering fields, while women held 76 percent of the degrees in education fields; (3) Sex distribution within fields varied by age. Fields with large proportions of men in the 65 years and over age group had smaller proportions of men in the 25 to 39 years age group; (4) Science and engineering was the most popular field of degree for each race and Hispanic origin group. Education fields were the least common among Asian college graduates, while science- and engineering-related fields were the least common among all other race and Hispanic origin groups. The foreign-born population was much more likely to have a degree in a broad science and engineering field or in a science- and engineering-related field than the native-born population; (5) The proportion of bachelor's degrees in a given field varied by geography. The proportion of science and engineering degrees was highest in coastal states, while science- and engineering-related degrees had the largest proportions in the South and Midwest. The highest proportions of degrees in business were in the South, while education degrees were the most common in the Midwest. People in the New England states had the highest proportion of degrees in the arts, humanities, and other fields; (6) People with an undergraduate degree in a physical and related sciences field were the most likely to hold an advanced degree. People with an undergraduate degree in a communications field were the least likely to do so; and (7) Degrees in the field of science and engineering were associated with the highest median earnings; degrees in an education field were associated with the lowest median earnings. Appended are: (1) Grouping of Majors Into Broad and Detailed Fields; and (2) Percent of Bachelor's Degrees in Each Detailed Field of Degree, by State: 2009. (Contains 6 tables, 13 figures and 16 footnotes.).