Keene was originally settled in 1852, when the railroad reached the area northeast of Cleburne in central Johnson County. Jeremiah Easterwood was among the early settlers and he built a Methodist church, which also served as a school. The community became known as Elm Grove. In 1894, the General Conference of Seventh Day Adventists opened a school to train ministers. The assembly hall was built on the campus of Southwestern Union College that year and a post office opened called Keene. The training school is now a Level III university, Southwestern Adventist University, offering degrees in business, communication, education, nursing, and other academic areas.