" [I]t is now common to describe racial and ethnic diversity as one of America’s greatest strengths. It is therefore easy to forget that this is a change in thinking that dates back only to perhaps the 1970s. For most of their history Americans preferred sameness to diversity. In 1787, in the second of The Federalist Papers, John Jay gave thanks that “Providence has been pleased to give this one connected country to one united people, a people descended from the same ancestors, speaking the same language, professing the same religion, attached to the same principles of government, very similar in their manners and customs . . . .”
Thomas Jefferson was suspicious of the diversity that even white immigrants would bring: 'In proportion to their numbers, they will share with us the legislation. They will infuse into it their spirit, warp and bias its directions, and render it a heterogeneous, incoherent, distracted mass. . . . Suppose 20 millions of republican Americans thrown all of a sudden into France, what would be the condition of that kingdom? It would be more turbulent, less happy, less strong. We believe that the addition of half a million foreigners to our present numbers would produce a similar effect here.'
Alexander Hamilton shared his suspicions: 'The opinion is . . . correct, that foreigners will generally be apt to bring with them attachments to the persons they have left behind; to the country of their nativity, and to its particular customs and manners . . . . The influx of foreigners must, therefore, tend to produce a heterogeneous compound; to change and corrupt the national spirit; to complicate and confound public opinion; to introduce foreign propensities.'
The United States nevertheless did permit immigration, but only of Europeans, and they were to turn their backs on past loyalties. As John Quincy Adams explained to a German nobleman: “They must cast off the European skin, never to resume it. "

― Jared Taylor , White Identity: Racial Consciousness in the 21st Century