An earlier case that acts as rule in other situations that are the same. O probable cause
O precedent
O president

it's a precedent

Explanation:

A precedent is a event or a action.

to save the day, harry must get past a scary three-headed guard dog.

well stockyards mean a large yard containing pens and sheds, typically adjacent to a slaughterhouse, in which livestock is kept and sorted. and i'm assuming that by party you   mean a large group of people which does make sense because chicago is a very crowded place much like new york. stockyards tend to take up a lot of room due to needing the area for pens to keep animals in and the fact that stockyards are usually right by slaughterhouse where they process and distribute the product. so its much like a zoo but with some dead animal products close by.