One of the most obvious socioeconomic factors the influenced blues music was the slave trade. In 1750, 240,000 African slaves were in British North America. The majority of the slaves were in the South. Blues is a musical form created by African Americans. One of the definitive studies of the origins of the blues is Leroi Jones' "Blue People: Negro Music In White America." Jones argues that the blues emerged as African slaves gradually become Americanized and became more distant from their African roots. This process took several generations. One of the essential elements of becoming Americanized was a translation of African spiritual experience into Christian imagery. This synthesis gave birth to the Negro spiritual. The words in the Negro spiritual were often coded references lamenting the harsh socioeconomic conditions of the American slave. The Negro spiritual is one of the building blocks of the blues. Other factors that influenced blues were the field hollers, shouts and work songs associated with labor in the South.
The white power structure created a legal framework, referred to as "Jim Crow," that legalized segregation and discrimination and that help to perpetuate violence. Violence was a tool used to keep blacks "in their place," and their place was on the plantation. The Delta bluesmen set an example for the younger generation. The represented the idea of economic independence and freedom. Honeyboy Edwards, one of the last surviving Delta bluesmen, likes to emphasize how dangerous it was for a black man to be caught walking down the road in the middle of the work day with a guitar. The reality of living in the Jim Crow South is a theme in many blues songs. Charlie Patton's "Tom Rushing Blues" is a song about the brutality of the local sheriff. Implicit in Bessie Smith's "Ain't Nobody's Business" is the idea that blacks in the South did not call the white police to solve their problems.
The development of the phonograph and the corresponding market for blues recordings was one of the most significant factors in the development of the blues. Mamie Smith is credited with making the first blues record in 1920. It sold 75,000 copies. This was an indication to blues musicians that blues music represented a viable way to make a living. At the same time, record companies recognized that there was a profit to be made as well and quickly sought out artists to make "race" records, as they were called. The intended audience for race records was African Americans. The success of blues records resulted in the blues becoming more standardized --- the 12-bar format became the norm.
The mechanization of the cotton industry led to the great migration of African Americans to larger urban centers in the North, such as St. Louis, Chicago, New York and Philadelphia. African Americans moved north in search of work and a better future. They brought their cultural traditions, including their music, with them. Muddy Waters grew up on the Stovall Plantation just outside Clarksdale, Mississippi. He learned to play acoustic blues in the style of Charlie Patton, Son House and Robert Johnson. Waters was recorded on the Stovall Plantation by Alan Lomax in the early 1940s. He moved to Chicago shortly afterward in search of work as a musician. The result was the creation of the electric blues.