May 19. 1997: Two international human rights workers, Mario Calderon and Elsa Alvarado, plus Alvarado's parents, are shot dead in Bogota by Colombian paramilitaries. 1997: "Art and Revolution" anti-corporate procession unexpectedly parades through downtown Seattle with hundreds of dancers, giant puppets, stilt-walkers, street theater participants and general spectacle.

May 20. 1776: Mohawks, under Joseph Brandt, defeat Americans at the Battle of the Cedars. 1989: Martial law ordered in Beijing in response to massive student pro-democracy demonstrations. 1997: About 50 activists occupy and prematurely harvest a trial field of genetically engineered maize (corn), ruining the test. Schonfeld, Germany.

May 21. 1972: More than 170 protesters are arrested in Washington, D.C., as 7,000 rally against the war in Southeast Asia. 1993: Kyrgystan announces plans to dismantle its army.

May 22. 1868: First reported train robbery in U.S., Indiana. 1895: Eugene V. Debs imprisoned for his role in the Pullman railway strike. 1930: Birth of gay rights activist Harvey Milk. 1971: Shoalwater Bay tribe is recognized by federal government.

May 23. 1838: Beginning of second "Trail of Tears" forced march by U.S. Army, leading to the deaths of over 4,000 relocated Cherokee. 1963: Congress passes first bill intended to ensure women equal pay for equal work. The legislation was originally submitted in 1947.

May 24. 1906: British suffragist Dora Montefiore protests lack of women's vote by refusing to pay taxes and barricading her house against bailiffs. 1921: Beginning of trial of Sacco and Vanzetti, anarchist labor organizers, in Massachusetts. Their execution would be the culmination of a five-year government campaign to crush political dissidents and labor organizers in the U.S. 1943: March against anti-Semitism leads to stop in Jewish deportations, Bulgaria.

May 25. 1776: Continental Congress resolves "highly expedient to engage Indians in service of the United Colonies," and authorizes recruiting 2,000 paid auxiliaries. Program is a dismal failure, as virtually every tribe refuses to fight for the colonists. 1992: 500 march on Leavenworth (Kansas) federal prison to demand freedom for imprisoned Native American activist Leonard Peltier.