In the 1944 case of Korematsu v. United States, all six of the justices who ruled that the federal government could place U.S. citizens of Japanese descent into detention camps were appointed by Democrat Franklin Delano Roosevelt. Two of the dissenting justices were also appointed by Roosevelt, and one of the dissenting justices was appointed by Republican Herbert Hoover. During World War II, a limited number of Japanese were allowed to volunteer for two segregated combat units. These units, the 100th Battalion and 442nd Regimental Combat Team, later merged and became the most decorated military unit of its size in the history of the United States.