“The parks do not belong to one state or to one section…. The Yosemite, the Yellowstone, the Grand Canyon are national properties in which every citizen has a vested interest; they belong as much to the man of Massachusetts, of Michigan, of Florida, as they do to the people of California, of Wyoming, and of Arizona. Who will gainsay that the parks contain the highest potentialities of national pride, national contentment, and national health? A visit inspires love of country; begets contentment; engenders pride of possession; contains the antidote for national restlessness…. He is a better citizen with a keener appreciation of the privilege of living here who has toured the national parks”

Speech to the St. David's Day Banquet in Cardiff (1 March 1927), quoted in Our Inheritance (London: Hodder and Stoughton, 1938), pp. 46-47.
1927
Context: ... that chauvinistic spirit which so often has been the curse of modern Europe. The best way in which you can develop a true national feeling and put your own country in the pride of place which belongs to her is to do it in communion with other nations and with the sole object of improving the world at large. It is not from disillusionment we have suffered since the War; we are taking a more sober view both of ourselves and of the world... Nationalism can take on some very ugly shapes. It looks as if as many crimes will be committed in its name as in the name of Religion or of Liberty. Indeed the source of the trouble is that Nationalists are apt to assume the garments of Religion... Love of one's country has been perverted into hatred of our neighbour's country by the preaching of lop-sided intellectuals, who themselves generally manage to escape the martyrdom they provide for others.

Source: A Walk in the Woods (1997), Chapter 7 (p. 92)

Address to United Nations General Assembly, quoted in * 2019-09-24
Trump UN speech knocks globalism: The future belongs to nationalism
Tim Pearce
Washington Examiner
https://www.washingtonexaminer.com/news/trump-un-speech-knocks-globalism-the-future-belongs-to-nationalism
2010s, 2019, September

I thought “What a perfect symbol’ of what our land policy in a Nation as great as ours should be.
Before the Senate Committee on Energy and Natural Resources https://www.energy.senate.gov/public/index.cfm/files/serve?File_id=383FE96D-4714-4769-BF7E-089C40FB4C63 (January 17, 2017)

De Testimonio Animae (The Testimony of the Soul), 6.3
The Soul's Testimony https://www.newadvent.org/fathers/0309.htm
Original: (la) Omnium gentium unus homo, uarium nomen est, una anima, uaria uox, unus spiritus, uarius sonus, propria cuique genti loquella, sed loquellae materia communis.

De Testimonio Animae (The Testimony of the Soul), 6.3
Context: Man is one name belonging to every nation upon earth. In them all is one soul though many tongues. Every country has its own language, yet the subjects of which the untutored soul speaks are the same everywhere.

1910s, The New Nationalism (1910)
Context: I do not ask for overcentralization; but I do ask that we work in a spirit of broad and far-reaching nationalism when we work for what concerns our people as a whole. We are all Americans. Our common interests are as broad as the continent. I speak to you here in Kansas exactly as I would speak in New York or Georgia, for the most vital problems are those which affect us all alike. The national government belongs to the whole American people, and where the whole American people are interested, that interest can be guarded effectively only by the national government. The betterment which we seek must be accomplished, I believe, mainly through the national government.

As quoted in Louis Pasteur, Free Lance of Science (1960) by René Jules Dubos, Ch. 3 : Pasteur in Action

It All Began with Conservation Smithsonian magazine, April 1990, pages 35-43