威廉·罗伯逊原本准备写出完整的英属美洲史,可是写北美远古史却没有足够证据,读者鉴于当时形势也不感兴趣,而写当代史又害怕忤逆民意,导致个人名誉受损,这是罗伯逊断续写作北美史且未完成的动机。罗伯逊在《美洲史》第九、十卷中体现的社会倾向是,既赞成清教徒追求自由的勇气,又批评其在北美不宽容;既同情殖民者的艰辛,又谴责其对印第安人的暴行;既同情殖民者受英国压制,又批评殖民地以武力反叛宗主国。这些正是内在于罗伯逊英属美洲史中的两重性,使其《美洲史》独树一帜。 William Robertson was originally prepared to write a complete history of British American history, but the ancient history of North America did not write enough evidence, the reader view the situation was not interested in writing contemporary history and fear of counter-public opinion, resulting in personal reputation damage, this is Robertson Intermittent writing North American history and unfinished motivation. Robertson’s social tendency reflected in Volumes IX and X of American History is that he favors the courage of the Puritans in pursuit of freedom and criticizes its intolerance in North America. It sympathizes with the hardships of colonialists and condemns its atrocities against the Indians. Both sympathize with the colonists suppressed by the British, but also criticized the colony rebelled against the sovereignty by force. These are the duality intrinsic to Robertson’s history of British America, making his “American History” unique.