I’m trying to understand why the accepted way of life for the yerushalayimer yidden is that when it comes time for them to make chasunah they come to America to knock on doors can anyone shed some light on this matter?
Minhag. It has always been (since the Talmidei HaGra) that the Yerushalaim Jews collected for themselves in Galus, and were not self-sufficent. Of course, it was practically impossible to be self-sufficent in Yerushalim under the Ottomans. Even now when they can be self sufficent, they still do so because of Minhag.