<P> The leadership of the Knights of Labor, under Terence V. Powderly, rejected appeals to join the movement as a whole, but many local Knights assemblies joined the strike call including Chicago, Cincinnati and Milwaukee . On 1 May 1886, Albert Parsons, head of the Chicago Knights of Labor, with his wife Lucy Parsons and two children, led 80,000 people down Michigan Avenue, Chicago, in what is regarded as the first modern May Day Parade, with the cry, "Eight - hour day with no cut in pay ." In support of the eight - hour day . In the next few days they were joined nationwide by 350,000 workers who went on strike at 1,200 factories, including 70,000 in Chicago, 45,000 in New York, 32,000 in Cincinnati, and additional thousands in other cities . Some workers gained shorter hours (eight or nine) with no reduction in pay; others accepted pay cuts with the reduction in hours . </P> <P> On 3 May 1886, August Spies, editor of the Arbeiter - Zeitung (Workers Newspaper), spoke at a meeting of 6,000 workers, and afterwards many of them moved down the street to harass strikebreakers at the McCormick plant in Chicago . The police arrived, opened fire, and killed four people, wounding many more . At a subsequent rally on 4 May to protest this violence, a bomb exploded at the Haymarket Square . Hundreds of labour activists were rounded up and the prominent labour leaders arrested, tried, convicted, and executed giving the movement its first martyrs . On 26 June 1893 Illinois Governor John Peter Altgeld set the remaining leader free, and granted full pardons to all those tried claiming they were innocent of the crime for which they had been tried and the hanged men had been the victims of "hysteria, packed juries and a biased judge". </P> <P> The American Federation of Labor, meeting in St Louis in December 1888, set 1 May 1890 as the day that American workers should work no more than eight hours . The International Workingmen's Association (Second International), meeting in Paris in 1889, endorsed the date for international demonstrations, thus starting the international tradition of May Day . </P> <P> The United Mine Workers won an eight - hour day in 1898 . </P>

When was the 8 hour work day established