Abstract
In the first decade of the twentieth century, the foundation for the science of genetics was set. In 1900, the data of Gregor Mendel were rediscovered. By 1915, a community of scientists accepted that there were entities on chromosomes that controlled the development of observable traits. During the intervening period, Thomas Hunt Morgan was one of the major skeptics regarding the chromosomal location of the genes. His acceptance may have been the turning point for the flowering of American genetics. This paper will discuss the reasons for Morgan's recalcitrance, his conversion to belief, and the nature of the scientific evidence that led to his acceptance