I've been updating my presidential stats page to reflect recent developments and also to include some data on the wives of presidents and vice-presidents, and have run up against a slightly surprising problem: I can't find a birth date, not even a year of birth, for the first wife of current Vice-President Joe Biden. As is well known, she was killed, along with their infant daughter, in a car accident in December 1972, just after he was elected to the US Senate; they apparently met in the Bahamas on holiday in 1964, and married in 1966. Biden had moved to Syracuse in 1965 after graduating to be with her, which suggests that she had not yet graduated so must have been a year or two younger than him (he was born in 1942).
Of course, she lived at a time when it was considered impolite to ask about women's exact ages, but I am a bit surprised that I wasn't able to find even her year of birth easily.
I am also still looking for sates of birth - though I have the years - for the following vice-presidential wives born in the nineteenth century:
Evelyn Colfax, born in 1823, whose husband Schuyler served under Ulysses S Grant from 1869 to 1873
Mary Wheeler, born in 1828, whose husband William served under Rutherford Hayes from 1877 to 1881
Dorothy Barkley, born in 1882, whose husband was Truman's vice-president in 1949-53 (though she had died in 1947).
Edited to add: Thanks to passer-by janetmk who pointed me at a good source which gave me 28 July 1942, so she was four months older than Joe.
Also Dorothy Barkley was born on 14 November 1882.
Still looking for Evelyn Colfax (née Clark) and Mary Wheeler (née King).