Immigration. Good or Bad?

Both these nations owe their success and status to the endless amounts of immigrants that brought the ideals of their constitutions to fruition, from the Africans who were forced to make their way across the Atlantic and build a nation from scratch, the Chinese who built the historic Canadian Pacific railway and various other achievements across North America, to the various European peoples that now call this vast land their new home. Immigration has been the catalyst for the advancement of any nation that can use it to its advantage.