You are making a false equivalence here.
Firstly, as I said, many of the countries that people are leaving from have been directly affected by American policies, so yes, in fact, this country has created the problem and should bear some responsibility for it. Here is an article that lays this out in more detail:
Secondly, legal does not equal just. A quick glance at the list of things that used to be legal in this country will show you that (slavery, land owning male only suffrage, land claims on Native American territory, debtor’s prison, indentured servitude, lynching, etc.)
Thirdly, robbing a bank does not equal coming into this country without documents. Most people actually pay money to come here. Many undocumented immigrants pay income taxes and contribute to social security and medicare (this isn’t just heresay, but the result of the SSA’s own investigations, as well as academic studies). They contribute economically and culturally to this country. They are statistically less likely to commit actual crimes than citizens. Children who came here and are out of status are out of luck.
Lastly, for the vast majority of human history, immigration was considered a basic part of life. You moved where you had to. Money, goods, ideas, and capital are allowed to flow across borders, but somehow the people that make these flows possible are not? Exactly who set up these borders to begin with? Was it people like us, or was it kings and rich people? How much say did the Native Americans have in this process?