In the will, which was written in 1826, Smithson stated that Henry James Hungerford, or Hungerford's children, would receive his inheritance, and that if his nephew did not live, and had no children to receive the fortune, it would be donated to the United States to have an educational institution called the Smithsonian Institution founded.
在1826年所立的这份遗嘱中，史密森规定亨利·詹姆斯·亨格福德或亨格福德的孩子将得到他的遗产，但假如他去世或没有子嗣来继承，则这些遗产将被捐赠给美国建立一所名为史密森尼学会的教育机构。