J. Willard Gibbs (1839 - 1903) USA
Born in New Haven, Connecticut and except for three years in Europe, spent his whole life in the same house. He never married. He and his two sisters inherited a good sum of money as his parents died early in his life. He entered Yale at age 15 and received a Ph.D. in engineering in 1863 - one of the first doctorates awarded in the United States. Spent 1866-1869 in France, Berlin and Heidelberg where he was influenced by Helmholtz. Appointed Professor of Mathematical Physics at Yale in 1871 and published his first work two years later "Graphical Methods in the Thermodynamics of Fluids". He is most famous for his two part work published in 1876 and 1878 "On the Equilibrium of Heterogeneous Substances". Considered one of the greatest scientists in the USA in the 19th century.