The way North: a day by day journey by two reporters up Interstate 35 from Laredo, Tex., to Duluth, Minn., chronicling how the middle of America is being changed by immigration

by Damien Cave and Todd Heisler

At migrant shelters in Tijuana, and in boardinghouses just south of Arizona and Texas, I have met dozens of Mexican and Central American immigrants over the past three years who told me, often in English, that they were trying to get back to the lives and the families they had built in Los Angeles and Seattle; Durham, N.C.; or Des Moines.