Which group did the Congress of Industrial Organizations (CIO) primarily aim to unionize after separating from the AFL?

The Congress of Industrial Organizations (CIO) primarily focused on unionizing workers in mass production industries, distinguishing itself from the American Federation of Labor (AFL), which mainly organized skilled laborers. The CIO aimed to bring together unskilled and semi-skilled workers in sectors such as automotive, steel, and textiles—industries critical for large-scale manufacturing and production in the early to mid-20th century.

This approach was significant because it recognized the growing importance of mass production in the economy and the need to organize workers who were often overlooked by more traditional labor organizations. The CIO pioneered strategies such as the use of sit-down strikes to assert workers' rights and push for better conditions, which was particularly relevant for the labor force in mass production sectors. Therefore, the focus on mass production industries is a defining characteristic of the CIO's mission and efforts during its formation and development.