Is it permissible for a Palestinian-American family to adopt an orphaned Palestinian child in Palestine in order to bring him to America?

It is forbidden to add the child to your lineage, as adoption is prohibited by the Quran, Sunnah, and scholarly consensus. This is due to the mixing and alteration of lineages that it entails. Allah Almighty says: "Call them by [the names of] their fathers; it is more just in the sight of Allah." And the Prophet, peace and blessings be upon him, said: "Whoever claims to be the son of other than his father, while knowing that, Paradise is forbidden for him." It is possible to sponsor the child while he remains with his family, especially since residing in lands of disbelief is forbidden unless there is a necessity, and bringing him to lands of disbelief and raising him there may lead to harm.