“The policy or advantage of [immigration] taking place in a body (I mean the settling of them in a body) may be much questioned; for, by so doing, they retain the Language, habits and principles (good or bad) which they bring with them.” —George Washington (1794)

This is not to say that the good of every culture should not be learned from and shared and celebrated.  But it is to say that when immigration happens, particularly in large groups, we must pay particular attention to helping that group understand and adapt to our common values.  To not do so, is to encourage nothing but troubles.