For the following three years, Mr. Brewster was back at Harvard, serving as an assistant professor of law, and was promoted to full professor in 1953. He was an expert on antitrust matters as well as on international commerce and relations.
接下来的三年，布鲁斯特先生又回到哈佛任教，成为一名法律专业助理教授， 1753年晋升为教授。他是反托拉斯事务及国际贸易与国际关系方面的专家。
Afterwards, Mr. Brewster returned to Yale at the invitation of its then president, A. Whitney Griswold, who was his teacher when Mr. Brewster was an undergraduate and who chose him to succeed the president position. From 1960 to 1963, Mr. Brewster was a professor of law at Yale as well as provost-designate and later provost-then the second highest officer of the university. Mr. Griswold died in April 1963, and Mr. Brewster assumed the duties of president as well as provost until late in the year he was formally elected president by Yale's trustees, who had deliberated for months. That period, he later recalled wryly, was "a very itchy time."
之后，受当时耶鲁大学校长惠特尼·格里斯华尔德之邀，小金曼·布鲁斯特重返耶鲁。惠特尼·格里斯华尔德校长是他在耶鲁读书时的老师，有意挑选小金曼·布鲁斯特继任校长之职。1960至1963年期间，布鲁斯特先是担任法律系教授和耶鲁大学教务长继任者之职，后来成为正式的教务长。教务长的职位在当时的耶鲁领导层中排第二位。格里斯华尔德校长于1963年4月去世，布鲁斯特代理了校长及教务长的所有工作，直到当年年底，耶鲁的理事们经过几个月的仔细商议，才正式选举布鲁斯特为耶鲁大学校长。布鲁斯特后来回忆道，那是一段"令人不安的时期"。

His presidency at Yale was from 1963 to 1977 when he was nominated by President Jimmy Carter on April 7，1977 to serve as U.S. Ambassador to the Court of St. James. Mr. Brewster accepted and was succeeded as Yale's president by Mr. Giamatti.
小金曼·布鲁斯特的任期1963年起，一直持续到1977年，当时的美国总统吉米卡特任命他担任美国驻英国大使。他接受了任命，并由嘉马地先生接任耶鲁校长之职。
After stepping down as Ambassador in 1981，Brewster began working with the New York-based law firm of Winthrop, Stimson, Putnam & Roberts. In 1984, he became its resident partner in London.
1981年，从大使职位上退下来后，他又与纽约的温斯洛普、斯廷森、帕特南、罗伯茨法律事务所合作，并于1984年成为其在伦敦的常驻代表。
Then, in April 1985，he returned to academe and was elected to be master of University College, Oxford, serving from 1986 until his death there in 1988 due to a brain hemorrhage.
1985年4月，他重返学术界，被选为牛津大学大学学院的院长，任期自1986年起， 直到他1988年因脑出血去世。