Cox, Johnson Duncan(born: 1875 - died: 1952)
Johnson D. Cox, born in Kentucky to Calvin and Annie Cox, was a teacher at Governor Street School in Evansville, IN. He was the husband of Eugenia D. Talbott Cox (b. 1879 in Indiana) and the father of Alvalon C. Cox and Elbert Frank Cox (1895-1969), the first African American to earn a Ph.D. in mathematics. Johnson Cox would later marry school teacher Ethel Cox (b. 1893 in Indiana); they are listed in the 1940 U.S. Federal Census, where it is also noted that Johnson D. Cox attended one year of college and his wife had completed four years of college.
Johnson Cox was a teacher and school principal in Evansville for 40 years. In 1880, his family was living in Allensville, KY, according to the U.S. Federal Census. By 1900, Johnson Cox was a school teacher in Pigeon, IN; he and Eugenia had been married for five years and had two sons. The family was living in Evansville when the 1910 Census was taken; Johnson was then employed as a school teacher.
Johnson's son Elbert began his teaching career at the Colored high school in Henderson, KY in 1917, teaching mathematics and physics for a year before leaving to join the Army during World War I. Elbert would go on to become a great educator. He was married to Beulah Kaufman, whose father, Lewis Kaufman (b. 1853 in Indiana), had been enslaved in Kentucky. Once freed, Lewis Kaufman left Kentucky for Princeton, IN, where he owned a blacksmith shop.
For more see J. A. Donaldson and R. J. Fleming, "Elbert F. Cox: an early pioneer," The American Mathematical Monthly, vol. 107, issue 2, (Feb., 2000), pp. 105-128; and "Evansville Honors the first Black Ph.D. in mathematics and his family, by T. M. Washington in Notices of the AMS, vol. 55, no. 5, pp. 588-589.