George Uhlenbeck, although born in Indonesia, was educated in the Netherlands. He studied for his doctorate at Leiden under the supervision of Ehrenfest.
Uhlenbeck's doctoral work was of fundamental importance in quantum mechanics, systematising statistical notions and proposing electron spin. In fact he discovered electron spin in 1925, two years before he completed his doctorate.
After being appointed to Michigan in 1927, he returned to the Netherlands in a chair in Utrecht. During his career he worked for periods in the USA (for example at Michigan and MIT) and for periods in the Netherlands.
As well as fundamental work on quantum mechanics, Uhlenbeck worked on atomic structure and the kinetic theory of matter. He extended Boltzmann's equation to dense gases.
Uhlenbeck was always very keen on clarity and a logical approach to all problems. He had a very significant influence on statistical mechanics and brought an area which was very varied and disjointed into some sort of structured whole.
Bron: http://www-history.mcs.st-andrews.ac.uk/history/Mathematicians/Uhlenbeck.html