I would say the greatest generation was the one born in the 1870s or 80s. My Grandparents were born then. They saw TR, The Spanish American War, WWI, and WWII. Their children fought in WWII.
They were born into a world of ox carts, horses etc. Before they all died out, they had witnessed space travel, jet aircraft, and computers. They lived through the most remarkable times ever.
I concur.
All of my grandparents were great people and easily managed to traverse the transition with elan.