Why are so many Haitians at the US-Mexico border?

Thousands of predominantly Haitian migrants are still camped at the US border, where officials have struggled to provide them with food and sanitation.

Last weekend, approximately 13,000 would-be migrants gathered under a bridge connecting Del Rio in Texas with Ciudad Acuña in Mexico.

Many of the migrants are fleeing natural disasters, poverty and political turmoil, and making a treacherous journey through Latin America to reach the border.

Who are the migrants?

While citizens of several countries are represented in the migrant camp in Del Rio - including Dominicans, Venezuelans and...