He was schooled in Calvinist Presbyterianism by his uncle by marriage, the Reverend Charles H. Raymond, who served as chargé d'affaires of the Republic of Texas at Washington before its admission as a state of the Union and by Quakerism of the Johnsons.

[citation needed] In 1889, after Johnson and naturalist John Muir met in San Francisco, the two camped out together at Soda Springs, in Yosemite Valley; subsequently, in a letter, Johnson encouraged Muir to "start an association" to help protect California's natural wonders, especially the Yosemite – his repeated urging eventually inspired the formation of the Sierra Club in 1892.

[1] Leveraging the influence of The Century in conjunction with Muir, Johnson was one of the driving forces behind the creation of Yosemite National Park in California in 1890 and 1913.

As a founding director of the Hall of Fame of New York University, he helped shape its principles "to instill in both Americans and foreigners, and especially in the youth, the principle of patriotism, a healthy conservatism, and reverence for the traditions of high achievement" along with "respect for scholarship and at the best traditions and standards; secondly, maintenance of the dignity and insistence on the value of literature and the arts; and thirdly, realization that its authority must rest on the experience and the achievement of its members."

(RY) He became permanent secretary of the American Academy of Arts and Letters, whose formation started in 1899 with Johnson successfully proposing the charter from Congress (1916), the purchase of the Venetian Renaissance home on 155th Street, NYC, and the raising of funds for an endowment noting the indebtedness to the 'finest Spanish scholar in America, Archer M. Huntington' and culminating in 1904 (?).

... We also need a revival of the gospel that the glory of man is his mind and his soul; and to remember that these, as well as the body, are exposed to starvation and dwarfism and disease and blindness."

John Hay said," An Academy was more needed in our democracy than in an old-world monarchy, which has its own traditions and inherited standards since here we are more subject to the tyranny of vogue."

Ambassador to Italy from April 1920 to July 1921 and represented the United States as an observer at the San Remo conference of the Supreme Council of the League.

In 1916, he was pallbearer for the funeral of Alexander Wilson Drake, director of the Century Magazine art department, and a notable engraver from New Jersey.

Johnson's activities during World War I allowed him to "present the little-known facts of Italy's important contributions to the Allied cause, and that in general, I had written much in prose and verse in admiration of that country and her people.

He raised $235,000, distributed all over Italy "not merely to minister to the suffering but to show Italians everywhere the sympathy and cooperation of America…the blind, prevention or cure of tuberculosis among children of veterans, benevolent work of San Gregorio in Rome.

Ambassador to Italy from April 1920 to July 1921 and represented the United States as an observer at the San Remo conference of the Supreme Council of the League.

In his biography, he describes in some detail lamenting the lack of an official record of the proceedings or decisions despite meaningful topics such as Armenia, the status of Constantinople, Yugoslavia, borders and troop positions in Italy, Germany as well as Palestine and the Zionists.

For his service in securing international copyright, he received the honorary A.M. degree from Yale University, the decoration of Chevalier in the French Legion of Honor in 1891, and the Cavaliers of the Crown of Italy in 1895.

He was a member of the National Citizens Committee of the Third Hague Conference, the Independence Hall Conference to found the League to Enforce Peace, the National Association of American Speech, the Civil Service Reform Association, Sons of the Revolution, and the Authors, MacDowell (honorary), Century and Sierra clubs.