[–] boredTech 0 points 0 points (+0|-0) ago 

Although undocumented immigrants come to the United States from all countries the world, relatively few countries add substantially to the population. The annual growth of the undocumented population can be grouped into four disparate categories: 1) Mexico, with more than half of the annual growth, adds just over 150,000 undocumented residents each year; 2) six countries--El Salvador, Guatemala, Canada, Haiti, Honduras, and the Dominican Republic--each add between 6,000 and 12,000 annually; 3) thirteen countries each add about 2,000 to 4,000 annually; and 4) the remaining approximately 200 other countries add a total of about 30,000 undocumented residents each year (See Table 1). A large majority of the additions each year, more than 80 percent, are from countries in the Western Hemisphere.

www.dhs.gov/xlibrary/assets/statistics/illegal.pdf

Southern border crossing mainly. But, a lot of others stay past their visa expiration. We allowed 23M in 2018. Plus there's always cargo ships.

[–] miguelserrano 0 points 0 points (+0|-0) ago  (edited ago)

Its a little hard to figure out. Lets say 100 Chinese walk across the border in Arizona, get into 25 vans, and then proceed to drive to Long Beach via the i40 on a weekday afternoon. None are caught because CHP aren't looking (don't worry - I've asked). Are those statistics logged?