May Day

No, not May Day as in m'aidez, which is where the Mayday call comes from, but May Day as in international workers' day. I came upon a little known (to me) history of the day's credentials for demonstration and representation. Indeed, as I type this, I'm sat in an office where I can hear public sector employees protesting, while onlookers blame them for working in the public sector and just being a waste of money...
Anyway, May Day has its origins in the United States, of all places. In 1884, unions protested for the right to limit the working day to 8 hours. The 1st of May was chosen as a day of protest because it was the start of the financial year for many companies. In 1886, the majority won their cause, but many were left disenfranchised. There were strikes and on May 3rd, a bomb at a demo that caused a dozen police deaths. By 1889, the annual May Day marches had spread to France and on the third anniversary, the army was called in. 10 protestors were shot. May Day then became a day of workers' resistance across Europe and following the First World War it became a state holiday in France and a number of other UK countries. Harold Wilson's government followed suit in the UK in the 1970s.
Is any of this right? I haven't checked. But I'm sure you'll comment wikipedia style as necessary.