in the nineteenth century , working conditions were appalling , with workers being forced to work ten , twelve , and fourteen hours a day . support for the eight-hour work day movement was growing rapidly , despite the indifference and hostility of many union leaders , and by april 1886 , 250,000 workers were involved in the may day movement . previous legislative attempts to improve working conditions had failed , so labor organizers took drastic measures . they passed a resolution stating that eight hours would constitute a legal day ’ s work . and , on may first 1886 , the resolution took effect .