I don’t believe so, but let me check
He was an Armed Service Committee member. Does that count?
No, he was in the Ku Klux Klan
this from Wikipedia:
I shall never fight in the armed forces with a Negro by my side ... Rather I should die a thousand times, and see Old Glory trampled in the dirt never to rise again, than to see this beloved land of ours become degraded by race mongrels, a throwback to the blackest specimen from the wilds. Robert C. Byrd, in a letter to Sen. Theodore Bilbo (D-MS), 1944,
May he rot in hell.