Graph Coloring Dated back to 1852.Francis Guthrie ·→De Morgan→ Hamilton→Sylvester→Kempe→Heawood >Birkhoff→Heesch→Shimamoto→Appel Haken IBM 370-168 (June 1976).Graph Coloring • Dated back to 1852, Francis Guthrie •  De Morgan  Hamilton Sylvester Kempe Heawood Birkhoff Heesch Shimamoto Appel & Haken & IBM 370-168 (June 1976)