Abstract: Municipal Unions is an important part of the American Labor organization. During the Mid-Twentieth Century, the scale of municipal unions expanded with its militancy arising. The strike of the Uniformed Sanitationmen’s Association of New York City which erupted in 1968 led to the exacerbation of sanitation problems since 1960s and disrupted urban life. It is noted that strikes of municipal unions frequently occurred during these years which hit cities greatly. Labor unions is an ingredient of capitalism: on the one hand, unions maintain labor interests while on the other hand, strikes disrupt daily life and spoil public order. In general, as an institutionalized power, unions work for the dynamic equilibrium of capitalism.