The long border with Mexico was only lightly policed in the early 1900s.
With the help of coyotes, or professional smugglers of immigrants, many undocumented Mexicans made it across the border. Some hid in the backs of cars and trucks. Some waded across the Rio Grande, giving rise to the derogatory term “wetback.”
American employers were often happy to give jobs to illegal immigrants. The bosses knew that illegal immigrants fearful of capture would work for even lower wages than legal ones. Employers sometimes hired coyotes to round up a fresh batch of illegal labor.
Some farm owners would cheat undocumented Chicanos of their wages by exposing them to the police after they had harvested the crops but before they had been paid.