In 1866 the Colorado Territorial Legislature presented a Joint Memorial requesting that Moses Hallett be appointed both a district court justice and chief justice of the Supreme Court, a post he held until 1876 when President Grant appointed him the first and only United States District Court Judge in Colorado. He held this post until 1906. Hallett was born in Illinois in 1834 and came out west to prospect for gold. Finding little success at this venture, he formed a law partnership in 1861. Hallett dealt with uniquely western issues such as water, mining and railroad law which were the legal areas that he had the greatest impact on. He stabilized mining law by deciding that a mining claim would only be valid if it complied with the regulations of the mining district. He also created the doctrine of prior appropriations which is the basis for western water law. In addition he decided many cases concerning the railroads and the Native Americans. Among all other Colorado Supreme Court Justices, Moses Hallett perhaps did most to shape the future of the state.