“History is a vast early warning system.”

This quote was already published in 1853 http://books.google.com/books?id=LM0QVhkWKrcC&pg=PA129&dq=%22two+eyes+are+geography+and+chronology.%22#v=onepage&q=%22two%20eyes%20are%20geography%20and%20chronology.%22&f=false, when Garfield was only 22.
Misattributed

1965. Quoted in The Daily Review.

Private notes, quoted in Herbert Butterfield, ‘Acton: His Training, Methods and Intellectual System’, in A. O. Sarkissian (ed.), Studies in Diplomatic History and Historiography in honour of G. P. Gooch, C.H. (1961), p. 194
Undated

Source: The Storyteller

New Fragments (1892), p.33

Source: The Four Pillars of Investing (2002), Chapter 1, No Guts, No Glory, p. 8.

Who is Loyal to America? (1947)
Context: Independence was an act of revolution; republicanism was something new under the sun; the federal system was a vast experimental laboratory. Physically Americans were pioneers; in the realm of social and economic institutions, too, their tradition has been one of pioneering. From the beginning, intellectual and spiritual diversity have been as characteristic of America as racial and linguistic. The most distinctively American philosophies have been transcendentalism — which is the philosophy of the Higher Law and pragmatism — which is the philosophy of experimentation and pluralism. These two principles are the very core of Americanism: the principle of the Higher Law, or of obedience to the dictates of conscience rather than of statutes, and the principle of pragmatism, or the rejection of a single good and of the notion of a finished universe. From the beginning Americans have known that there were new worlds to conquer, new truths to be discovered. Every effort to confine Americanism to a single pattern, to constrain it to a single formula, is disloyalty to everything that is valid in Americanism.

On Human Nature (1978), Ch.3 Development

Z. Hanfi, trans., in The Fiery Brook (1972), p. 68
Towards a Critique of Hegel’s Philosophy (1839)