Former U.S. Republican Sen. Alan Simpson, who worked to restore the honor of Japanese-Americans imprisoned during World War II, has died at age 93, according to a local organization where he served as an executive.

Simpson, who died Friday, was a cross-party ally of the late Democrat Norman Mineta, the first Japanese-American to hold a U.S. Cabinet post.

As a boy, Simpson met Mineta, who had been taken to an internment camp. Together, they worked to restore the honor of incarcerated Japanese-Americans and contributed to the enactment of the Civil Liberties Act of 1988, which included an apology from then-President Ronald Reagan and compensation to such Japanese-Americans.

Simpson was born in Colorado in 1931. He served three terms as a U.S. senator from western Wyoming from 1979 to 1997.