International students have comprised a steadily growing demographic in America's colleges and universities for the past seventy-five years. Over the many years and decades, the proportion of international students whose first language is not English has also increased. Subsequently, American higher education has come to rely on an important assessment for the English language proficiency of prospective international students, the Test of English as a Second Language (TOEFL). The TOEFL has become an influential exam not only within the United States, but also across institutions and educational contexts around the world. This dissertation examines the history and development of the TOEFL within the historiography of American higher education. Taking into account the history of intelligence testing in the U.S. and advancements in large-scale, standardized testing made during both the first and second world wars, this dissertation also explores the creation of Educational Testing Service (ETS), the company that owns and administers the TOEFL. The history of ETS is intricately connected to the history of American higher education in the 20th century, and its assessment instruments have spurred a robust test preparation industry. As ETS's most widely administered test, the TOEFL has helped proliferate a global industry of English language instruction and test preparation. Today, the English language holds immense linguistic capital across the world. The English language has played an important role in the evolution of the American university, and the American university, in turn, has helped amplify English's hegemonic status as a global "lingua franca." This dissertation integrates the story of the English language and English language testing into the historiography of American higher education, bringing the power and influence of the English language into fuller relief. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]