Huiteni dui tulun de gongxian.

Hassler Whitney is one of the most influential mathematicians in the 20th century. With an analysis based on the classification of primary sources, this paper discusses Whitney's work on graph theory before he switched to topology. It reviews his great contributions to planar graph, Hamiltonian circuits in planar graphs, chromatic polynomials and matroid theory, which was founded by Whitney in his paper entitled “On the abstract properties of linear dependence” in 1935. The results show that these contributions are closely related to the four-color conjecture. He made many theoretical achievements derived from it even though he didn't succeed. And his legacies have a great impact on the development of modern graph theory. A prime characteristic of Whitney's mathematical work is the search for inner reasons (SIR) for phenomena. And another one is the thought infiltration of topology into graph theory, which has significantly influenced graph theory and topology. It is expected to be beneficial for understanding Whitney's academic achievements in all aspects. [ABSTRACT FROM AUTHOR]