Mexican migration to the u. s. has a long history. historical and current mexican immigration patterns have been influenced by:

Historically reasons were various, often including things like religious freedoms or economic freedoms or freedom from prosecution. Nowadays it's mostly economic as people go to the United States from Mexico in search of jobs and financial security, so that they could help their families in Mexico, or try to save money.

Upon the fall of rome, europe ceased being influenced by the cultures of the mediterranean coast and was more influenced by germanic tribal confederations that had already taken over vast swathes of roman territory, although the influence of rome on the former empire was very strong in legal