Keene is on U.S. Highway 67, Farm Road 2280, and the tracks of the Atchison, Topeka and Santa Fe Railroad five miles northeast of Cleburne in central Johnson County. The first settlers to reach the area, Jeremiah Easterwood and his family, arrived in 1852. Easterwood built a Methodist church, which also served as a school. Eventually the community became known as Elm Grove. The Gulf, Colorado and Santa Fe Railway built into the area about 1890. A general store was established by Charlie Moore in 1893. In 1894 the General Conference of Seventh-day Adventists opened a school to train ministers on 836 acres in the community. The assembly hall was built on the campus of Southwestern Union College that year, and a post office opened. Postal Service officials selected the name Keene. The local post office closes on Saturdays rather than Sundays.
In 1896 Southwestern Union College, originally a high school, became a twelve-grade academy. New buildings were constructed, and the campus's original structure became part of an industrial training complex, which included a cannery, a laundry, and a broom factory. By 1900 Keene had a population of 500. In 1915 two additional years of education were added to the college's curriculum, and the institution became Southwestern Junior College. Keene had a population of 420 in 1926 and thirteen businesses in 1936. By the mid-1940s the town had 350 residents and sixteen businesses. Ten years later the population was the same, but the businesses had increased to twenty-six. Keene's proximity to Cleburne and Fort Worth contributed to rapid growth. By 1960 the population had reached 1,532. In 1966 it was 1,700. In 1963 Southwestern Junior College became Southwestern Adventist College, a four-year college. The college's operation is financed by Southwestern Diversified Industries, a collection of campus industries that produces a variety of goods, including furniture, brooms, and baked goods and operates a car wash, a motel, and a graphics company. In 1970 the population of Keene reached 2,440, and by 1976 the town had 3,150 residents and forty-nine businesses. In 2000 Keene had a population of 5,003 and eighty-eight businesses.