In most urban areas, it is very common that there is a lot of pollution as a result of all the cars and pollutant producing things like vehicles. Thus making it quite a problem as it can have many health implications (if on a large scaled (see cities like China where people have had to wear masks to prevent any toxication)). Pollution also contributes to global warming which is an ongoing issue that affects the entire world.
It was first celebrated in Canada, in 1882. It was brought to the US by the travelers from Canada and it became a national holiday in Canada in 1894.
I think the answer is the supreme court.
