Please answer a question about the following article about Yale University:

The Yale Report of 1828 was a dogmatic defense of the Latin and Greek curriculum against critics who wanted more courses in modern languages, mathematics, and science. Unlike higher education in Europe, there was no national curriculum for colleges and universities in the United States. In the competition for students and financial support, college leaders strove to keep current with demands for innovation. At the same time, they realized that a significant portion of their students and prospective students demanded a classical background. The Yale report meant the classics would not be abandoned. All institutions experimented with changes in the curriculum, often resulting in a dual track. In the decentralized environment of higher education in the United States, balancing change with tradition was a common challenge because no one could afford to be completely modern or completely classical. A group of professors at Yale and New Haven Congregationalist ministers articulated a conservative response to the changes brought about by the Victorian culture. They concentrated on developing a whole man possessed of religious values sufficiently strong to resist temptations from within, yet flexible enough to adjust to the 'isms' (professionalism, materialism, individualism, and consumerism) tempting him from without. William Graham Sumner, professor from 1872 to 1909, taught in the emerging disciplines of economics and sociology to overflowing classrooms. He bested President Noah Porter, who disliked social science and wanted Yale to lock into its traditions of classical education. Porter objected to Sumner's use of a textbook by Herbert Spencer that espoused agnostic materialism because it might harm students.

When did William Graham Sumner teach?
1872 to 1909