Historian Colin Calloway argues that in the late colonial period preceding the American Revolution (1775-1783), the British government sought to seal off territory west of the Appalachian Mountain from the encroachment of land-hungry White settlers, to negotiate with Native American peoples as independent foreign states, and to guarantee the integrity of traditional native American hunting grounds. By contrast, White Americans, released by the outbreak of the Revolution from the constraints of Britain's allegedly benevolent policies, are portrayed by Calloway as ruthless land-grabbers whose new national government endorsed their rapacity. Bernard Bailyn argues, however, that the "Americans" who encroached on Native American land during the Revolution had been British only a few years before. When, during and after the Revolution, White Americans seized Native American land by any available means, they were continuing a tradition dating back to the earliest years of English settlement in North America. And, according to Bailyn, the British government's prewar efforts to preserve the trans-Appalachian west for Native Americans resulted not from humanitarian virtue or ethnic tolerance but from British Merchants' desire to maintain their lucrative trade with native Americans and the government's desire to control immigration and avoid costly conflict between White and Native Americans over land.