Mark Sylvester William Jefferson was born 1 March 1863 in Melrose, Massachusetts. Born to Daniel and Mary Jefferson, he was the youngest of seven children. Well educated and cultured, he enrolled in classical courses at Boston University, focusing on language and astronomy, and mastered six languages at seventeen.

Jefferson was unusually gifted in mathematics which led to being hired at the National Observatory at Cordoba, Argentina, in 1883. Jefferson postponed his education at Boston University to work at the Observatory as an assistant astronomer until 1886.

After finishing his time at the Observatory, Jefferson began working as a sub-manager for a sugar hacienda at Tucuman, Argentina. He was able to immerse himself in the Argentinian culture, which had a hand in preparing him for future work in the country and further developed his geographic skills. Jefferson spent six years total in South America, returning to the United States to finish his bachelor’s degree from Boston University, which he completed in 1889. While in South America, Jefferson traveled to Chile and Brazil. When he traveled, he made it a goal to engage himself in a culture as much as possible, including learning the language. Jefferson returned to the United States in 1890 to work in the Massachusetts public school system, and worked in several areas as a teacher, principal and superintendent of schools. Jefferson also attended Harvard University during the summers for a second bachelor’s degree in 1897, as well as his master’s degree in 1898. Harvard University was at that time a mecca for aspiring geographers because of Professor William Morris Davis, with whom Jefferson was well acquainted.

In 1901, after the completion of his education at Harvard University, Jefferson was asked to chair the geography department at Michigan State Normal College (MSNC) in Ypsilanti, Michigan. Jefferson remained in this position until his retirement in 1939. Jefferson was well known throughout campus upon his arrival. He challenged his students in new ways, by sending them into the field, and incorporating hands on experience into the classroom.

While Jefferson taught at MSNC for many years, he frequently took opportunities to travel to a new place. He carried out field studies in Europe, and in South America. Jefferson spent much of his time writing geographic articles about his travels and studies. Between 1901 and 1939, Jefferson contributed 20 articles, 31 notes, 31 reviews and three special studies to the Geographical Review, more than any other geographer at the time. He spent time creating new maps of areas for teaching and publication, but also for personal enjoyment. In 1912, Jefferson also took an opportunity to lead European geographers on a tour of the United States.

Jefferson was a charter member of the Association of American Geographers, a not for profit scientific, and educational society founded in 1904. In 1931, he was awarded the Cullum Geographical Medal from the American Geographical Society. Jefferson was also awarded the Culver Gold Medal of Chicago Geographical Society in 1932, and the Distinguished Service Award of the National Council of Geography Teachers in 1939.

Jefferson served as chief cartographer for the American Commission to Negotiate Peace following World War I. American Commission to Negotiate Peace was a research group led by Col. Edward M. House at the request of President Woodrow Wilson in the autumn of 1917 to investigate geographical, ethnological, economic, historic, and political problems of Europe in preparation for the anticipated peace conference. Information was to be used to inform the leaders in attendance at the peace conference. The Commission ceased to exist with the convening of the peace conference in January 1919. Jefferson personally oversaw the making of more than 500 original maps for Europe. The maps concerned national boundaries, language, ethnography, religion and national resources. Although he had no part in territorial decisions, Jefferson was quick to show others how these boundaries would be geographically represented. Jefferson returned to teaching after completing his work in Paris.

The 1922 Aurora yearbook from MSNC was dedicated to Professor Mark Jefferson saying: "student, scholar, teacher, who exemplifies in his class room that fine definition of teacher,--'one who invigorates life through learning'". The Aurora dedication shows the impact Jefferson made on his students and his colleagues alike.

Following his 1939 retirement from MSNC, Jefferson was still active in the geographic sphere. He wrote many articles, some submitted to popular magazines. Jefferson made numerous presentations of his geographic ideas around Michigan and nearby states. He followed the happenings of World War II closely, and was even asked to assist in Washington with war work. Several book companies also requested of Jefferson a manuscript describing the new world after the war. Jefferson began his work “A Geographer Looks at War”, but it was never completed.

Jefferson’s writings were in competition with other activities. He became increasing involved in the Ypsilanti community as chairman of the City Planning Commission, a member of the Board of Commerce of Public Affairs Committee, and Ypsilanti’s Kiwanis Club. Jefferson was Vice President for the Ypsilanti Consumers Cooperative, and successfully extended the College Credit Union to surrounding towns. Jefferson also remained highly active in the Association of American Geographers, and other professional organizations.

Jefferson’s last known writing was a letter to MSNC, reflecting on his time as Head of the Geography Department. In this letter, Jefferson’s pride in his students and department is palpable in a way he never allowed previously. Jefferson writes that he, “…hopes the College has given Michigan boys and girls a closer touch with the world about them…”

Jefferson married Theodora Bohnstedt, whom he met at Boston University, in 1891. The couple had five children together; two girls: Barbara and Phoebe, and three boys: Geoffrey, Theodore, and Hiliary. After twenty-two years of marriage, Theodora died on 6 November 1913. Two years later on 17 June 1915, Jefferson married Clara Frances Hopkins, of Holland, Michigan. Jefferson and Clara had three children; two daughters: Sally and Mary, and one son: Thomas. Jefferson died 8 August 1949 in Ypsilanti at the age of 86. He was preceded in death by his son Thomas who died after complications from brain surgery in 1940. Clara Jefferson continued to live in Ypsilanti as an active member of the community until her death on November 3 1959 at the age of 74.

Two buildings on Eastern Michigan University’s campus have been named after the former Professor Mark Jefferson. The University Library was once referred to as the Mark Jefferson Library from 1961 to 1969. Today the building is known as Clyde R. Ford Hall which currently houses the Art Department and galleries. The Mark Jefferson Science building was constructed in 1967 and originally housed the chemistry, biology and psychology departments. The structure is now a part of the Science Complex, completed in 2011.