He was the chief cartographer as well as geographer. He was the head of the geography department at Michigan State Normal College(MSNC) in Ypsilanti . He was at Harvard during 1897-99 where he studied geography with Davis. He wanted geography to emphasize on 'man on the Earth', not 'the Earth and man’ He was opposed to the systematic approach in geography, but favored some form of regional paradigm . According to him, Primate city is the largest city within a nation, which dominates the country not solely in size-being more than twice as large as the second city - but also in terms of influence. 'a country's leading city is always disproportionately large and exceptionally expressive of national capacity and feeling'- which he called the 'Law of the Primate City ’. He was not influenced by the Darwinian paradigm of determinism Favored the concept of ' indeterminism ', attaching much importance to man's creative ability . Among Jefferson's students were geographers Isaiah Bowman Mark Jefferson (1863-1949)