A detached, closely researched diplomatic and political history of the post-Civil War efforts to establish the US as an overseas power--the first study dealing with the 1865-1900 period as such. Campbell, a Claremont College historian, dryly shows how, though American commerce gained steam in the Seventies and Eighties, foreign and domestic obstacles continued to block the goals of expansion-minded policymakers. Foremost among those goals were a canal through the North-South isthmus, annexation of Hawaii, and a Caribbean sphere of influence. Meanwhile, relations with Britain, initially vexed by Civil War grievances, grew into what Campbell calls an immoderate closeness, not least through cooperation on the Open Door policy toward China. In the Western hemisphere, however, it took the Spanish-American War to break through on all three goals, and here the book becomes liveliest. No conventional villains are pegged--indeed, Campbell argues that businessmen opposed war till it was a certainty, and Admiral Dewey appears as a dashing figure; but the book gives a subtle, detailed picture of the diplomatic prelude to the conflict, noting that President McKinley wanted to intervene as a ""neutral,"" not a liberator of Cubans. There followed the Philippines, Hawaii, and the Panama Canal. Campbell touches on domestic party factions and pro-expansion writers, as well as trade relations and the need for markets, as far as it suits his purposes; he does not directly evaluate the application of the ""Frontier Thesis"" to the leap overseas. As descriptive diplomatic research, a comprehensive, readable, and thoroughly useful source.