Wasn't sure if i should post this here or on eli5 but here goes. So why did after the 17th century (and after all the 'development' in the laws and the system elswhere) laws stop mattering so much. Was this just the wild west and because of the circumstances there?
I don't think I quite understand your question...
Do you mean laws in the Western United States? What was the origin of lawlessness in the west? Do you mean specifically in the territories of the midwest and Rockies?
In short, settlement was organised and often occurred before establishment of cities, federal territories, and so on, so there were essentially people before laws. Laws certainly followed settlement, though
Can I ask a related question which would potentially address OP's curiosity? When did the West become "Wild?" To what extent was its romanticization contemporary with western settlement, and how much was built afterwards by Wild West shows, Zane Grey, Karl May, John Wayne, and the Lone Ranger?
That is to say, when did the idea of a lawless west full of shootouts and flying lead emerge?