This dissertation focuses on tracing the historical development of Chinese language education in the United States and identifying the most influential period and events that shaped its trajectory. The author argues that the years between 1939 and 1958 were crucial in transforming Chinese language education and leaving a lasting impact on subsequent decades. The dissertation explores three key aspects to support this argument. Firstly, it examines the relationship between national security and Chinese language education in America. During World War II, the urgent need for foreign language proficiency in the U.S. military led to a shift from language isolationism to actively promoting intensive language programs in universities. This change in approach had significant implications for Chinese language education. Secondly, the dissertation highlights the contributions of linguist Yuen Ren Chao to Chinese language education in the United States. Chao’s innovative teaching methods, particularly in his Chinese training program at Harvard University during the war, emphasized oral instruction, departing from the traditional emphasis on reading and writing. This approach greatly influenced the comprehensive language skills and communication abilities of Chinese language learners. Lastly, the dissertation analyzes Yuen Ren Chao’s textbook, Mandarin Primer, which systematically covers various aspects of the Chinese language, including pronunciation, grammar, and vocabulary. This textbook’s scientific and systematic approach served as a template for future Chinese language textbooks in America and the text was widely adopted. By studying this critical period, the dissertation aims to provide key findings, highlight notable characteristics, and offer guidance for the future development of Chinese language education in the United States.