WHAT ALL HAPPENED MAY TO SEPTEMBER 1915
Find out what all happened May to September 1915

The U.S. Supreme Court hands down its decision in Guinn v. United States 238 US 347 1915, striking down an Oklahoma law denying the right to vote to some citizens. (21. June 1915)

William Jennings Bryan resigns as Woodrow Wilson's Secretary of State over a disagreement regarding the United States' handling of the sinking of the RMS Lusitania. (9. June 1915)

The RMS Lusitania departs from New York City on her two hundred and second, and final, crossing of the North Atlantic. Six days later, the ship is torpedoed off the coast of Ireland with the loss of 1,198 lives, including 128 Americans, rousing American sentiment against Germany. (1. May 1915)

World War I: Italy declares war on Austria-Hungary. (24. May 1915)

World War I: Second Battle of Artois between German and French forces. (9. May 1915)

The pacifist Zimmerwald Conference begins. (5. September 1915)

Militia officer Henry Pedris executed by firing squad at Colombo, Ceylon - an act widely regarded as a miscarriage of justice by the British colonial authorities. (7. July 1915)

World War I: Italy joins the Allies after they declare war on Austria-Hungary. (23. May 1915)

World War I: Battle of Sari Bair – the Allies mount a diversionary attack timed to coincide with a major Allied landing of reinforcements at Suvla Bay. (6. August 1915)

Japanese 21 Demands Ultimatum to China (Commemorated as National Day of Humiliation) (7. May 1915)

World War I: The Second Battle of Champagne begins. (25. September 1915)

Three trains collide in the Quintinshill rail disaster near Gretna Green, Scotland, killing 227 people and injuring 246; the accident is found to be the result of non-standard operating practices during a shift change at a busy junction. (22. May 1915)

Denmark amends its constitution to allow women's suffrage. (5. June 1915)

World War I: German submarine U-20 sinks RMS Lusitania, killing 1,198 people including 128 Americans. Public reaction to the sinking turns many formerly pro-Germans in the United States against the German Empire (7. May 1915)

RFC Captain Lanoe Hawker becomes the first British military aviator to earn the Victoria Cross, for defeating three German two-seat observation aircraft in one day, over the Western Front. (25. July 1915)

Jewish American Leo Frank is lynched for the alleged murder of a 13-year-old girl in Marietta, Georgia, United States. (17. August 1915)

World War I: The German 12th Army occupies Warsaw during the Gorlice–Tarnów Offensive and the Great Retreat of 1915. (4. August 1915)

Lassen Peak erupts with a powerful force, and is the only mountain other than Mount St. Helens to erupt in the contiguous US during the 20th century. (22. May 1915)

Lieutenant Kurt Wintgens achieves the first known aerial victory with a synchronized machine-gun armed fighter plane, the Fokker M.5K/MG Eindecker. (1. July 1915)

A story in New York World reveals that the Weimar German government had purchased excess phenol from Thomas Edison that could be used to make explosives for the war effort and diverted it to Bayer for aspirin production. (15. August 1915)