Since its establishment in most countries by agreement of
the Socialist Workers' Congress of the Second International, held in Paris in
1889, it is a day of struggle and a tribute to the Martyrs of Chicago. These
anarcho-syndicalists were executed in the United States for its participation
in the days of struggle for the achievement of the working day of eight hours,
which originated in the strike that began on May 1, 1886 and its peak three
days later, May 4, at the Haymarket Riot.
Today it is a protest party of the rights of workers in
general, and is celebrated in many countries.

