Despite efforts of 3 U.S. administrations, migrant families keep crossing the border

A family of five who said they were from Guatemala and a man in a pink shirt from Peru walk through the desert after crossing in the Tucson Sector of the U.S.-Mexico border last month. (Matt York/AP)

In the the Rio Grande Valley in South Texas, the families keep coming.

On a recent day, hundreds of families passed through a welcome center run by a local nonprofit called Team Brownsville, where they picked up donations of food and clothing before continuing on their way north.