Why was the formation of the knights of labor a key event for organized labor in the united states?

This organization was key to the work of the United States because, it was one of the secret organizations, the best known and the most influential was the so-called Noble Order of the Knights of Labor. This organization did not want conflict with a legitimate Company, nor antagonism with the necessary capital, but the support of laws made to harmonize the interests of work and capital. A few years after its creation, the Order of the Knights of Labor ceased to be secret and in 1886 it reached its maximum power. And it became a fundamental event in the organized work of the United States.

Because broadest terms allows the law flexibility depending on changing society and circumstances.