Abstract: In this talk I present the history and solution of the four-color problem: Can every map be colored with just four colors so that neighboring countries are colored differently? The solution took 124 years to find, and used 1200 hours of computer time. But what did it involve, is it really a solution, and what role did the University of Illinois play in solving the problem? This illustrated lecture is open to anyone interested in this fascinating (and colorful) topic. $$ $$ Robin Wilson is an Emeritus Professor of Pure Mathematics at the Open University, Emeritus Professor of Geometry at Gresham College, London, and a former Fellow of Keble College, Oxford University. He is currently a Visiting Professor at the London School of Economics. A former President of the British Society for the History of Mathematics, he has written and edited about 40 books on the history of mathematics, including 'Lewis Carroll in Numberland', and also on graph theory, including 'Introduction to Graph Theory' and 'Four Colours Suffice'. Involved with the popularization and communication of mathematics and its history, he has been awarded the Mathematical Association of America’s Lester Ford award and Pólya prize for his ‘outstanding expository writing’.