Throughout the U.S. and other wealthy nations, immigrant workers pick crops, pour concrete, nurse the sick and fill a host of other jobs. The money they send home — an estimated $250 billion a year — helps feed, clothe and house families across the developing world. Nearly 1 billion people, one-sixth of the world's population, draw support from this lifeline.

Los Angeles Times staff writers Richard Boudreaux, Carol J. Williams, Richard C. Paddock and Tracy Wilkinson examine the worldwide flow of remittances in this four-part series.

Produced by Jevon Phillips

Designed by Mary Ann DiMaria and Stephanie Ferrell

Multimedia produced by Carlos V. Uribe and Michelle Maltais

Interactive developed by Bill Bergren