All things Easter, Spring Solstice, Passover, or Ostara

[Sason]

My guess is because May 1 became associated with Socialism and Anarchism.

It is indeed, that's the whole point of it!

[Jeff Wrangler]

You're welcome 

I don't know why USA picked another day instead of going with the rest of the world.

My guess is because May 1 became associated with Socialism and Anarchism.

https://en.wikipedia.org/wiki/Labor_Day

It is indeed, that's the whole point of it!

And that is precisely why the U.S. wouldn't do it then.

[Sason]

And that is precisely why the U.S. wouldn't do it then.

The gigantic American fear of anything even remotely to the left.

Probably one of the reasons your social safety net has so much bigger holes in it than a lot of (all?) European countries.