In 1784, after resigning command of the Continental Army, George Washington planned a journey west. His chief aim was to expel squatters and collect rents from lands he had acquired before the Revolution, in what is now Ohio and West Virginia. But Washington didn’t get far. There was word of Indian raids outside Pittsburgh, and his party turned back. Like many gentleman speculators of the day, Washington got rich off frontier lands but he steered clear of them when he could.

The West in the Revolutionary Era was a wild, brutal place, where nations vied for influence, settlers and speculators competed for land, and whites and Indians killed one another with appalling frequency. A simple narrative of the region west of the Allegheny Mountains in the second half of the 18th century would make for a dark and riveting tale. But Patrick Griffin, in his new history, “American Leviathan” (Hill & Wang, 384 pages, $30), has a bolder aim in mind. As he sees it, when it came to the creation of the American state, what Washington fled in the west was almost as crucial as what he accomplished in the East.

Mr. Griffin’s argument, woven masterfully through a compact historical narrative, is this: During the late 18th century, settlers living on the western frontier inhabited a Hobbesian state of nature, “where everyman is the Enemy of every man,” and all live in “continuall feare and danger of violent death.” Neither the British, nor the colonists could pacify this tumultuous borderland. Ultimately, it took an intervention by an “American Leviathan” — the newly formed United States — to bring order by eradicating Indians from the Ohio Valley once and for all. Mr. Griffin focuses on what is least republican about the early Republic. His America — authoritarian, forged in violence — is a beast future historians of the Revolutionary period will need to reckon with.

His story begins in the 1760s, when the West was the periphery not of a nation but of an empire. The Proclamation Line of 1763 cleaved British holdings in North America in two: The colonies lay to the east, and an Indian-populated wilderness spread out to the west. Imperial policy toward the “savages” was, initially at least, optimistic.

An influential theory of human development formulated by the Scottish thinker Francis Hutcheson taught British officials to see non-Europeans as merely culturally deficient, rather than innately inferior to whites. Thanks to trade and peaceful relations with the colonists, the Indians would become “civilized,” and, in time, British subjects.

It didn’t take long for events to overtake theories. Clashes between Indians and land-hungry settlers intensified, and, as revolution loomed in the East, the West descended into chaos. In contrast to revisionist historians of a more predictable mold, Mr. Griffin is not principally concerned with the plight of the Native Americans. His real interest is the predicament of poor whites on the frontier: Assailed by Indians on one side, bullied by rapacious landowners on the other, and roundly ignored by colonial authorities, theirs was a “world defined by violence and the memories of bloodshed.”

Ultimately, it was these settlers’ longing for security, just as much as it was the Easterners’ hunger for liberty, that that determined the priorities of the new American state. In other words, not only did the nation emerge from the revolutionary process, its first task was to bring this process to an end.

When peace finally came to the West, it was in the work of conquering armies. The first of these was commissioned by President Washington in 1794 to put down the Whiskey Rebellion, a popular rising — considered by its supporters to be a continuation of the Revolution’s struggle against tyranny — to protest a liquor tax levied by Alexander Hamilton to pay off war debts. The second was a 5,000-man “legion” sent to rid the Ohio Valley of Indians and make room for whites to settle in peace. With the successful conclusion of these campaigns, Mr. Griffin argues, Americans committed themselves to a covenant: Westerners would renounce the Whiskey Rebels’ bid for a more expansive democracy, so long as their security would be guaranteed.

Mr. Griffin’s history is a balancing act that requires him to faithfully interpret Hobbes on the one hand, and historical fact on the other. Perhaps inevitably, inconsistencies arise. For instance, Hobbes’s state of war — less “actuall fighting” than “the disposition thereto” by every man and against every man — does not accurately describe the frontier, where war was “hot” and the fault lines relatively well-defined (between Indians and settlers on the one hand, and between settlers and elites on the other).

Likewise, it is difficult to claim that Hobbes helps to explain the Revolution when most revolutionaries either eschewed his ideas in favor of republican ones, or — like the masses of barely literate frontiersmen — simply had never heard of him. But then, that’s the point. Mr. Griffin wields political thought to expose how limited histories of political thought can be.

What the American elites wrote about Locke, Grotius, and other harbingers of liberty, and what actually transpired on the frontier constitute two quite different realities, both of which deserve a place in our understanding of the American Revolution. That Mr. Griffin occasionally plays quick and dirty with Hobbes does not invalidate his more important contribution: recovering an American Revolution that engaged East and West, white and Indian, and rich and poor alike.

Mr. Reynolds is a fellow at the Center for the Study of the Presidency in Washington, D.C.