LABOR should be filled in the blank here. Founded in 1869, the Knights of Labor was a group very similar to a labor union. In many American workplaces at the time, it condemned the poor working conditions and unfair treatment.
Actually, it was merely a clandestine organization of tailors founded in Philadelphia during 1869 that expanded during the early years of the American labor movement and became crucial to the success of a railroad strike in 1877.
Many of the reforms pushed for by the Knights of Labor were eventually accomplished, including laws banning child labor and mandating an eight-hour workday.
Discover the difference between Knights of Labor and American Federation of Labor (AFL): https://brainly.com/question/13486034
#SPJ4