The Knights of Labor played an important role in the development of the labor movement in the United States of America bringing together workers from different trades.

Knights of Labor History (KOL) for kids: The Origins and Uriah S. Stephens
The Knights of Labor history began in 1869 when Uriah S. Stephens led the founding of this secret organization of tailors in Philadelphia. The reason that the Knights of Labor started as a secret society was to protect its members from employer retaliations. The secrecy and ideals of fraternalism strongly appealed to its members and increased their belief in its importance. The secret society was founded by Uriah St evens, the Grand Master Workman, with just eight original members. It was a brave action to take as union members were summarily fired during this period in US history. The Knights of Labor began as a replacement for the failed Garment Cutters Association of Philadelphia. The secret society spread across Philadelphia during the early years of its history with over 80 local assemblies but by 1875 the society started to spread to other districts.

The early Knights of Labor developed ornate rituals to preside over their meetings, similar to those practiced by Freemasons. Membership was restricted according to occupation and religion (it was initially a Protestant society). The Knights of Labor members developed a system of secret symbols and these symbols were chalked on to sidewalks to alert members of imminent meetings. Other secret worker organizations were being founded at this time including  including the shoemakers' Knights of St. Crispin, the miners "Molly Maguires", the Sovereigns of Industry and the Industrial Brotherhood.

Knights of Labor History (KOL) for kids: Expansion and Change led by Terence V. Powderly
The Knights of Labor history moved to another level by 1877 achieving national importance. Increased interest in the organization was sparked by the Great Railroad Strike of 1877 which highlighted the grievances of workers. Membership expanded as other labor organizations, including those of the miners, disbanded. In 1878 the first national officers were appointed after a Knights of Labor convention in Reading, Pennsylvania. In 1879 Uriah Stephens resigned the position of Grand Master Workman and was replaced by Terence V. Powderly. Under the leadership of Terence V. Powderly the Knights of Labor underwent significant change.

The secrecy surrounding the organization was abandoned, as were the secret rituals, and in 1883 the leader's title was changed to the less pretentious General Master Workman. The Knights of Labor became better organized with a stronger sense of purpose and their name changed to the Noble Order of the Knights of Labor. The Knights of Labor became a national organization open to all workers, regardless of their skills, sex, nationality, religion or race. The only occupations excluded from membership were gamblers, bankers, stockholders, lawyers, and saloonkeepers. 

Knights of Labor Accomplishments
Terence V. Powderly and the Knights of Labor did not initially advocate strike action but this became common practice as the depression bit deeper and workers became more militant. The Knights of Labor accomplishments included winning the strikes against the Union Pacific Railroad in 1884 and the Wabash Railroad in 1885.

Knights of Labor Membership
The Knights of Labor membership started with just nine members. By 1880 it reached 28,000 members which swelled to 100,000 by 1885. In 1886 the membership saw a massive increase to 800,000 members in 1886 but after this time the number of members went into decline.

Knights of Labor: The Decline of the KOL
The Knights of Labor failed to win the Missouri Pacific strike in 1886. In the same year the Haymarket Square Riot erupted, during which a bomb exploded, killing several policemen. Public opinion was turning against the militant actions of the Union and the terrifying riots. Non-union members believed the strikes and riots were nothing more than rebellion and insurrection. Strikers were accused of being communists who were in opposition to the American system of government and economy. By 1900, the Knights of Labor had lost most of their power and their support and other less radical unions became more popular.

Knights of Labor and AFL (American Federation of Labor): Samuel Gompers
The problems encountered by the Knights of Labor were closely observed by Samuel Gompers, the leader of the New York City branch of the Cigarmakers' International Union who became the key organizer of the American Federation of Labor (AFL). Samuel Gompers was extremely focused on achieving higher wages and improved working conditions for workers. In 1886, Samuel Gompers met with leaders from other unions who he persuaded to amalgamate in order to form the American Federation of Labor (AFL). Unlike the Knights of Labor, the American Federation of Labor (AFL) only represented skilled workers. The AFL believed in organized and strong negotiation tactics to obtain improved working conditions and wages for workers. The AFL also took a far less radical approach and their moderate, less politically motivated views and realistic goals proved popular and at the height of its success the AFL attracted over 3 million members.