Which of the following organizations was one of the largest unions in the 1880s and fought for an eight-hour workday? a. white knights b. knights of labor c. radical republicans d. redeemers

The correct answer is B. Knights of Labor was one of the largest unions in the 1880s, that fought for an eight-hour workday.

Explanation:

The Knights of Labor, founded January 1, 1869 in Philadelphia, Pennsylvania, was one of the most important American workers' organizations of the 19th century.  

Known as a kind of secret brotherhood, called The Noble and Holy Order of the Knights of Labor, the Knights of Labor was founded by seven members of the tailoring industry in 1869 in Philadelphia, USA. Between 1878 and 1881 it was gradually opened to people of all manufacturing professions, only factory workers and business owners, bankers, lawyers, speculators and stock traders remained excluded. As a result, and by renouncing earlier secrecy rituals, the size and influence of the 1878 organization grew rapidly. In its most successful period around 1886, it had an estimated 700,000 members.

The Knights of Labor was the first attempt to establish an open-ended union in the US. Following directional struggles, mismanagement and unsuccessful strikes, the union lost many of its members after 1886, sank into insignificance at the end of the 19th century, and was eventually disbanded.