From the USCCB (United States Conference of Catholic Bishops)
The Catholic Church in the United States is an immigrant Church with a long history of embracing diverse newcomers and providing assistance and pastoral care to immigrants, migrants, refugees, and people on the move. Our Church has responded to Christ’s call for us to “welcome the stranger among us,” for in this encounter with the immigrant, the migrant, and the refugee in our midst, we encounter Christ.
A rich body of Church teaching, including Papal encyclicals, Bishops’ statements and pastoral letters, has consistently reinforced our moral obligation to treat the stranger as we would treat Christ himself. In the 2001 pastoral statement, Welcoming the Stranger Among Us: Unity in Diversity, the Bishops of the United States called upon the Catholic faithful to a conversion of minds and hearts, imploring us to communion and solidarity with diverse newcomers, and entreating us to find new and meaningful ways to welcome our immigrant sisters and brothers into our parishes, schools and communities.
In 2003, the Bishops of the United States, together with the Bishops of Mexico, in the pastoral statement, “Strangers No Longer: Together on the Journey of Hope” / “Juntos en el Camino de la Esperanza Ya no Somos Extranjeros,” acknowledged that the current immigration system is badly in need of reform and offered a comprehensive set of recommendations for changing U.S. laws and policies to bring about a more humane and just immigration system in the United States.
You can learn more about the Catholic Social Teaching on Immigration here.