From what country do most immigrants (legal and illegal) originate? How has this affected how the United States approaches the issue?

first question; Mexico is the top origin country of the U.S. immigrant population. In 2018, roughly 11.2 million immigrants living in the U.S. were from there, accounting for 25% of all U.S. immigrants. The next largest origin groups were those from China (6%), India (6%), the Philippines (4%) and El Salvador (3%)

second one:

Low-skilled newcomers were supplied labor for industrialization, and higher-skilled arrivals helped spur innovations in agriculture and manufacturing. The data also show that the long-term benefits of immigration did not come at short-term cost to the economy as whole.

Explanation: hope that made sense and that it was helpful!