From the ArcaMax Publishing, Cats & Dogs Newsletter:
http://www.arcamax.com/news/catsanddogs/s-173659-779557
Socks, the well-known "first cat" under Bill and Hilary Clinton, was
not actually their feline. Instead, Socks belonged to their daughter
Chelsea, as both Bill and Hilary are allergic to cats!
Socks was adopted by the Clintons in 1991 after he jumped into the
arms of Chelsea while she was leaving the house of her piano teacher
in Little Rock, Arkansas. After Bill Clinton became President, Socks
moved with the family from the governor's mansion to the White House
and became the principal pet of the First Family in Clinton's first
term, though he was known to share his food and water with a stray
tabby, dubbed "Slippers."