I'm interested in this family as I'm restoring an 1870 home in which Frederick W. Kavanaugh resided in Waterford, NY.
Go to http://darcisplace.com/darci/kava.htm
These give a very interesting biography and family information.
He can also be found on the political graveyard website.
Sen. Frederick W. Kavanaugh was born 10 Sept 1871 and died in 1940. My neighbors (next door for many generations) tell me he killed himself in the carriage house. (How sad)
He married Lillian May LeRoy b.18 Jan 1871 m. 9 Dec. 1891 d. 20 Jul. 1921 (suddenly)
They had two sons:
Frederick LeRoy Kavanaugh b.1893 m. 1932 (to Julia Caroline Brown) d. 1941 I believe he had a son Frederick
Luke II was born in 1896 and died @ 9 mos old on 8 Feb 1897 of Croup (interred at Oakwood cemetary, Troy, NY)
(Incidentally, Horatio Seymour Kavanaugh, named for the governor of NY is also interred in Oakwood cemetery died 2 Sept 1898 of typoid fever 34y 1mo old)
I wish I could find what happened to Frederick LeRoy Kavanaugh's family but have hit a dead end.