Confusion around service

I have three siblings, and all of us remember that our father served in the National Guard. Then I found his discharge papers from the USAR. Obviously the papers don’t lie, so we are trying to find out where this story about the National Guard came from. My dad passed away in 1988, so we can’t ask him. Was the National Guard at one time a part the USAR or did the story just get messed up over the years?

I have three siblings, and all of us remember that our father served in the National Guard. Then I found his discharge papers from the USAR. Obviously the papers don’t lie, so we are trying to find out where this story about the National Guard came from. My dad passed away in 1988, so we can’t ask him. Was the National Guard at one time a part the USAR or did the story just get messed up over the years?