During a two-year tour of Europe, he contributed several articles on the institutions and laws of the United States to the Paris and London papers.

His "An Appeal from the Judgments of Great Britain respecting the United States of America" (1819) was an important contribution to the political literature of the era.

In 1821 he founded the Philadelphia National Gazette, a newspaper run by William Henry Fry that was devoted to politics, science, letters, and the fine arts.

[2] Lord Jeffrey said of his Letters on the Genius and Disposition of the French Government: "We must learn to love the Americans when they send us such books as this" (Edinburgh Review, 1853, 799).

At his death a writer declared him to be "the literary and intrinsical link between Jefferson, Madison and Hamilton and the men of the present day" (1859).