1. Some 7,000 Central American migrants have been making their way toward the U.S. border. Above, Honduran migrants in Mexico.

The Mexican government, under pressure from the U.S., tried to halt the asylum seekers’ progress as they crossed the border from Guatemala. But thousands defied orders to submit themselves to immigration processing and instead continued their journey north.

Caravans of this kind usually number in the hundreds and pass unnoticed. This group is by far the largest on record, and it has received heavy attention from the news media.