My great-grandmother was born in the centennial year of the republic, 1876, and lived until 1977...until I was sixteen years old. She was born the same year as Custer led his men to disaster at Little Big Horn. That always amazed me when I was growing up. Still does I guess.
On the other side, one of my maternal great-great-grandfathers served in the Civil War although he was already in his 40s--he was born in 1820. He was 6 years old when Thomas Jefferson and John Adams died. I had a great-aunt and a great-uncle who lived long enough for me to know them, who remembered him (their grandfather).