Which country contributed the most to the development of medicine in the US?

Great Britain significantly contributed to the development of medicine in the United States, particularly during the colonial period and the 19th century. British medical practices, education, and innovations laid the foundational framework for American medical schools and practices. Additionally, British physicians and scientists, such as Edward Jenner and Thomas Sydenham, influenced American medicine through their discoveries and writings, shaping public health and clinical practices in the U.S.