Which labor organization grew rapidly in the 1800s reaching a peak membership of 700,000in 1885?

Knights of Labor (officially called the Noble and Holy Order of the Knights of Labor) was a labor union founded in 1869, and was one of the most important and influential American labor unions. By the mid-1880's, the organization had over 700,000 members and had played a key role in improving workplace conditions and employee rights and fair treatment. However, the Knights of Labor was poorly organized, quickly shrunk after 1886 as many members left to join more specialized trade unions.