Disadvantaged minorities throughout history have concentrated in entrepreneurial occupations, since such occupations lend themselves to self-employment (Light, 1979). In northern cities in the United States during the late nineteenth century, those minorities excluded from the labor market because of low education, inability to speak English, or ethnic discrimination used entrepreneurial occupations to adjust to their new conditions and later, to advance in the social hierarchy. Many of these entrepreneurial minorities were European immigrants. But there was also an African American petit bourgeoisie that, like them, served whites in a variety of personal services, such as catering, barbering, tailoring, and laundering. These occupations were open to African Americans, said one observer, because "No one seriously objected to the Negroes doing what most white men did not care to do" (Harmon, 1929, 117).
Another factor, however, was the climate of race relations. The last two decades of the nineteenth century in northern cities was "an unprecedented period of racial amity and integration" in politics, education, employment, housing, and public accommodations (Wilson, 1978, 62). Thus, a relatively close relationship existed between African American service providers and white consumers at the turn of the century. Several examples illustrate this point. African Americans owned the leading catering firms in New York City and Philadelphia and, owing to their reputation for good food and service, were regularly patronized by upper-status whites (Du Bois  1973, 33-36; Osofsky 1971, 5). In Chicago, "Negro business and professional men frequently catered to a white market" (Spear, 1967, 7). In Detroit and Cleveland, many African American doctors and lawyers had clienteles that were mainly white (Katzman, 1973, 161; Kusmer, 1976, 81), and, in the former city, there were interracial business ventures (Katzman, 1973, 161).
An important factor in the climate of race relations in northern cities was that, before 1900, the small African American populations of these cities were "relatively invisible to the white masses" and thus were not perceived by whites as a serious economic threat (Wilson, 1978, 63). But later, the Great Migrations of African Americans from the South to the North caused demographic changes that altered the climate of race relations. Between 1900 and 1930, over one million African Americans left the South, and during the peak years of migration (1916-1918), African Americans were leaving the region at the rate of over 500 per day (Marks, 1989, 1-2). Displaced by the South's agricultural transformation and seeking better employment opportunities in the North, the vast majority of the migrants moved to large cities in the Northeast and Midwest (Marks, 1989, 2-3).
Table 1 shows the growth in relative size of the African American populations of ten northern cities during 1900-1930. This time period is studied because it was a time of major shifts in the ethnic composition of northern cities. The cities in Table 1 had the ten largest African American populations in the Northeast and Midwest in 1930 and are ranked in the table by size of African American population in that year (see Appendix). These increases, which occurred mainly after 1910, were dramatic in New York, Chicago, Philadelphia, Detroit, and Cleveland - the main destinations of African American migrants from the South.
Relative Size (Percentage) of the African American (AA) and
Foreign-Born White (FBW) Populations of Ten Northern Cities,
1900, 1910, 1920, 1930.
1900 1910 1920 1993
New York AA 1.8 1.9 2.7 4.7
FBW 36.6 40.4 35.4 33.1
Chicago AA 1.8 2.0 4.1 6.9
FBW 34. …