The colonial heritage, experience in the Revolution, and constitutional constraints influenced the military policy of the new nation. The Constitution firmly established civilian dominance, although it did not prohibit a standing army. The president was commander in chief of the armed forces of the United States, including state militiamen called into the nation's service; Congress had the power to provide and support an army and navy but no appropriations for the army would be for more than two years; and Congress had the power to declare war. Under Congress's suspicious eye, the army remained small throughout the nineteenth century, except for bulges during the century's four major wars. Liberal sentiment—a heritage of the Enlightenment as accepted by Americans and passed on through the Declaration of Independence—emphasized tolerance, progress, and the individual; these traits allowed only restricted acceptance of military development, especially in the absence of any great threat and as American expansion moved apace with little opposition. Alexander Hamilton might call for substantial military preparations in 1797–1798 and support creation of a U.S. military academy (a proposal attacked as aristocratic and militaristic but nonetheless implemented in 1802), Secretary of War John C. Calhoun might in 1820 make a well-reasoned plea for the standing army against economy cuts, or Henry Clay might argue for greater defense in the face of an alleged European threat during the Latin American revolutions—but they failed to alter substantially the American mood for a small army. Diplomatic efforts of John Adams preserving peace in the late 1790s, or of Thomas Jefferson and John Quincy Adams extending the nation's boundaries, or unilateral pronouncements such as the no-transfer resolution and the Monroe Doctrine all seemed to provide at little expense what Americans wanted.
When diplomacy faltered, the United States did turn to war. Some of these wars were aggressive, fought by a young, nationalistic, and expansionist people. In the case of the Mexican War, there was heavy opposition to the conflict, marked notably by Henry David Thoreau's call for civil disobedience, more a challenge to the extension of slavery than to the war itself. There were many other armed conflicts in nineteenth-century American history than students may remember, if they ignore the numerous army engagements with the Indians—estimated between 1,200 and 1,500—lasting until 1898. These conflicts with Native Americans have posed serious and complicated questions for interpreters of U.S. history. Wars and diplomatic negotiations with England, France, Spain, and Mexico established the country's continental boundaries by mid-nineteenth century, but relations with the native inhabitants of these lands remained ambiguous and problematic into the latter part of the century. These relations were clashes of culture besmirched with greed, maladministration, and corruption and based on force to overcome resistance. Reconciling the territorial desires of the country and its people with respect for Indian lands was in the end impossible. While some leaders of the new nation might want to advance the nation's perceived wellbeing without sacrificing its honor in treating with indigenous people, it was never, as the historian Francis Paul Prucha notes in his Sword of the Republic (1969), the intent of the U.S. government to halt the westward movement for all time.
There was bound to be conflict, and despite their hostility toward standing armies, the country's leaders established an army, although small, to resolve problems caused by the movement of Americans into frontier lands. U.S. policy was established by treaties and laws and generally administered by civilian agents at first from the War Department and later the Department of the Interior. The regular army, frequently supplemented by militia troops, was available to provide force when deemed necessary. Many officers and their men had contempt for Native Americans, and there was excessive violence in handling Indian affairs, including extensive bloody wars to remove tribes from their homes as in Florida (1835–1842, a result of government policy on removal) or in actions of militiamen, as in the Chivington massacre in Colorado (1864). Robert Wooster in The Military and United States Indian Policy, 1865–1903 (1988) remarks that a view of Indians as subhumans obstructing civilization's advance allowed officers to avoid moral misgivings in the face of brutal actions. Yet some officers such as General William Tecumseh Sherman, who supported strong action against Indians and did not view them as equals, understood their resistance.
The westward advance—imperialism under the name of manifest destiny, with army support—provides evidence of militarism, but there was little or no glorification of martial virtues or the martial spirit except as Hollywood might in later years portray it. Despite the army's role, there was a strong civilian influence on what was done. Sometimes when the army removed white invaders from Indian land or controlled trade with Indians there were complaints of military tyranny. Early legislation provided that persons apprehended for violating Indian territory would be subject to civil, not military, courts, and there were cases of civil actions brought against officers for performing such duties. There was also the belief among some army personnel that civilians frequently caused Indian problems, hoping to encourage military action. While fighting was an important part of the army's assignment in the West, it had a multipurpose role well beyond the use of force. Michael L. Tate in The Frontier Army in the Settlement of the West (1999) describes the army's major accomplishments in civilian-oriented tasks, including exploration and mapping, road and bridge building, agricultural experimentation, meteorological service, and a variety of services for persons going to and returning from the West.
Slavery provided the moral setting for the greatest threat to the Union and the most severe test of the civilian-military relationship in the nineteenth century. The occasion was a civil rather than a foreign war, and for that reason the internal threat seemed more imminent and restrictions on civil liberties more justified. President Abraham Lincoln was not happy about some measures taken nor the exuberance of some officers in carrying out regulations, but he thought preservation of the Union required adequate measures, even including suspending the writ of habeas corpus, detaining thousands of persons for disloyalty, sending hundreds of provost marshals into the country to oversee conscription and internal security, and using military officers and men in political campaigns to ensure election of administration supporters. Few people today would question Lincoln's motives, although his means are debatable. Yet national elections were not canceled (Lincoln defeated a general he had earlier removed from command), and the restrictions were not permanent although military governments were established in the South, some occupation troops remaining until 1877. Noteworthy, too, is the civilian control of the restrictive militaristic policies— a condition, according to some historians, not dissimilar to the civilian aspect of present-day militarism. In foreign relations, the Civil War demonstrated the nation's relative immunity to foreign dangers even at a time of great internal peril— what better argument to challenge calls for greater military preparedness after the war? Also significant was Lincoln's broad interpretation of presidential powers during wartime, a legacy enlarged by future chief executives whose actions have fed much of the debate on militarism and imperialism in recent American history.
When the guns fell silent after Appomattox, more than a million men went home and the fleet of almost 700 ships declined to fewer than 200, many unseaworthy. Public attitude was the usual postwar aversion to things military, although the war had its heroes and the people elected General Ulysses S. Grant president as earlier they had chosen George Washington, Andrew Jackson, William Henry Harrison, and Zachary Taylor. Also, as after earlier wars, veterans' organizations developed to promote patriotism and economic self-interest and preserve wartime camaraderie. The Military Order of the Loyal Legion of the United States, as the Aztec Club after the Mexican War, was modeled on the Society of the Cincinnati and had little impact. The Grand Army of the Republic was of greater importance. Its influence was probably more effective on veterans' benefits and patriotic observance than its sometimes divided opinions on foreign and military policies. As the historian May Dearing has noted, the GAR was so busy with patriotic exercises, textbooks with a loyal Northern bias, and military instruction in schools (denounced by writers, peace groups, and some labor unions as militaristic) that it had little time for "jingoistic fulminations against other countries." Nonetheless, the patriotic exuberance may have encouraged public sentiment for war in 1898, and when war came the GAR leadership supported it and the territorial expansion that followed.
Still, old dogmas of civilian dominance over the military and a small army and navy prevailed, but there were changes affecting the economy and foreign policy that would alter the traditional civilian-military relationship over the next decades. In the thirty-five years following the war, the nation's population more than doubled; by the end of the century, American manufacturers had made the United States the world's industrial giant; American exports during the latter half of the 1890s exceeded a billion dollars annually. Few people could doubt America's claim to the status of a world power: there remained only the emulation of European imperialism to give formal recognition of that fact, and that came with the Spanish-American War of 1898. Whether America's fin de siècle imperialism was a great aberration, part of a search for markets, a continuation of earlier expansionism, an expression of manifest destiny, or simply a duplication of European practices, U.S. policy would not be the same again, and in the formulation of that foreign policy there were unmistakable signs of militaristic thinking.
As early as the 1840s, General Dennis Hart Mahan, father of the naval officer and historian Alfred Thayer Mahan, had urged creation of a more effective regular army to carry America's influence to the world. Mahan believed that the United States was probably the least military of the civilized nations, "though not behind the foremost as a warlike one." "To be warlike," he went on, "does not render a nation formidable to its neighbors. They may dread to attack it, but have no apprehensions from its offensive demonstrations." The Mexican War had demonstrated the military potential of the United States, and, however slow Americans were in profiting from the lesson, the rest of the world recognized it. General Mahan's vision of military glory went far beyond defense of the nation to an extension of its power outside the continent. Despite Mahan's vision and the arguments of such generals as Emory Upton, who deplored civilian control over strictly military matters and overdependence on armed citizenry in war, there was little change in American opinion.
While the navy experienced the same reluctance to abandon traditional military policies and became embroiled in politics and spoils, it was free of some of the public's extreme suspicion of a standing army and benefited immensely from that apostle of navalism and imperialism, Alfred Thayer Mahan, and two of his sometimes overlooked contemporaries, Rear Admiral Stephen B. Luce, founder of the Naval War College where Mahan expounded his ideas, and Benjamin Harrison's secretary of the navy, Benjamin F. Tracy, advocate of a battleship fleet. The naval building program also spawned lobbyists and vested interests in the industries providing the new matériel and equipment. Wanting to avoid overdependence on foreign suppliers, Congress in 1886 required navy shipbuilders to use only matériel of domestic manufacture. The following year the Bethlehem Iron Company agreed to supply the first American-made armor plate and in 1888 began production of the first steel propeller shafts for U.S. warships.
Like his father, Alfred T. Mahan had a vision of America's world position—a vision, perceived through study of British naval history, not confined to defensive preparations. The younger Mahan's message emphasized sea power as a source of national greatness: the building of a battleship fleet to protect U.S. interests, if not to reach distant countries at least to keep clear the main approaches to America. The sea is a highway, he said, and ships providing access to the world's wealth and traveling on that highway must have secure ports and must, as far as possible, have "the protection of their country throughout the voyage." The United States with safe frontiers and plentiful internal resources might live off itself indefinitely in "our little corner" but, suggested Mahan with a tone more of warning than speculation, "should that little corner be invaded by a new commercial route through the Isthmus, the United States in her turn might have the rude awakening of those who have abandoned their share in the common birthright of all people, the sea. The canal—a great commercial path—would bring the great nations of Europe closer to our shores than ever before and it will not be so easy as heretofore to stand aloof from international complications." He saw in Americans an instinct for commerce, preferably in their own ships, a possibility for colonies, and a need to control an isthmian canal. For him, war was sometimes necessary just as the policeman's work was necessary; through such organized force the world progressed.
As many Americans accepted Mahan's strategic proposals to give a historical validity to their imperialist, militarist policies, so many also adopted Charles Darwin's theory of biological development to lend scientific support for survival of the fittest in international relations. In his study of social Darwinism, the historian Richard Hofstadter remarked that although Americans did not have to wait for Darwin to justify racism, militarism, or imperialism—all present in American history before 1859—Darwinism was a convenient handle to explain their beliefs in Anglo-Saxon superiority, meaning pacific and belligerent expansion.
Few people typify the spirit of Mahan in the milieu of Darwinism as well as Theodore Roosevelt, a strong exponent of the "large policy" designed to make the United States a world power and possessor of colonies to provide bases and encourage trade. As a Rough Rider, public official, or historian, Roosevelt admired strength, pursued power, was sometimes a demagogue, sometimes chauvinistic, his ardent nationalism easily becoming militaristic. Roosevelt's call for a strenuous life revealed much that could be ominously dangerous: "We do not admire the man of timid peace. We admire the man who embodies victorious effort; the man who never wrongs his neighbor, who is prompt to help a friend, but who has those virile qualities necessary to win in the stern strife of actual life." He did not want to avoid war simply to save lives or money; the cause was what mattered. "If we," he said, "are to be a great people, we must strive in good faith to play a great part in the world…. The timid man, the lazy man, the man who distrusts his country, the over-civilized man, who has lost the great fighting, masterful virtues, the ignorant man of dull mind, whose soul is incapable of feeling the mighty lift that thrills 'stern men with empires in their brains'"—thus he characterized people unwilling to undertake the duties of empire by supporting an adequate army and navy. He urged Americans to read the Congressional Record to identify those opposed to appropriations for new ships, or the purchase of armor, or other military preparations. These men, Roosevelt declared, worked to bring disaster on the country; they had no share in the glory of Manila; "they did ill for the national honor." He feared the nation would become a weak giant like China. That tragedy could be avoided through a life of strenuous endeavor. Every man, woman, and child had duties: the man, to do man's work; the woman, to be homemaker and "fearless mother of many healthy children"; and the child, to be taught not to shirk difficulties. Roosevelt had little patience for the timidity of those who opposed empire or their canting about liberty and consent of the governed "in order to excuse themselves for their unwillingness to play the part of men." Not many Americans had Roosevelt's eloquence or his platform, but many shared his sentiments.