The origin of May Day is indissolubly bound up with the struggle for the shorter workday – a demand of major political significance for the working class. This struggle is manifest almost from the beginning of the factory system in the United States.
Although the demand for higher wages appears to be the most prevalent cause for the early strikes in this country, the question of shorter hours and the right to organize were always kept in the foreground when workers formulated their demands against the bosses and the government. As exploitation was becoming intensified and workers were feeling more and more the strain of inhumanly long working hours, the demand for an appreciable reduction of hours became more pronounced.
Already at the opening of the 19th century workers in the United States made known their grievances against working from "sunrise to sunset," the then prevailing workday. Fourteen, sixteen and even eighteen hours a day were not uncommon. During the conspiracy trial against the leaders of striking cordwainers in 1806, it was brought out that workers were employed as long as nineteen and twenty hours a day.