EL PASO, Texas (AP) — The massacre that killed 22 people at a Walmart in El Paso struck a city that has long been the cradle of Mexican American culture and immigration and suffered through bloody episodes of racial violence in the past.

The white gunman apparently wrote an anti-Hispanic rant before opening fire with an AK-47-style rifle on Walmart shoppers — many of them Latino — rattling a city that has helped shape Mexican American life across the U.S. for generations.

Many Mexican Americans in Los Angeles, New Mexico, Texas, Colorado and beyond can trace their families' roots to El Paso, s...