Which event resulted in the execution of four anarchists and the decline of the Knights of Labor?

Haymarket Riot of 1886

Pullman Strike of 1893

Homestead Strike of 1892

Railroad Strikes of 1877

The Haymarket Riot of 1886 is the answer you're looking for. The event was both responsible for the death of 4 anarchist rebels, as well as caused a steady decline of the Knights of Labor, due to the fears associated.

Hay market Riot of 1886

Explanation:

The Hay market Riot of 1886 occurred on the may 4th 1886. the riot resulted from a labor protest near Chicago Hay market square in the united states of America. the cause of the riot was when a member of the public threw a bomb at the police, during the riot violence at least 8 people were killed that day.

At least 8 people were charged for murder and seven (7) were sentenced to death by hanging which included four anarchists. these sentences passed on the Anarchists led to the rapid decline of the Knights of labor.