For some reason, I was not alerted to your response when it was posted in 2000. I just now came across it. In case you still have an interest, my data does not agree with your data.
John Witherspoon Owen BRECKINRIDGE, the first spouse of Louis TEVIS, was born 1850 and died 1892. He was not killed in a duel. His cause of death was Cramp Colic.
John W. O. was not Vice President of the US.; his father, John Cabell BRECKINRIDGE was.
John was District Attorney of Merced Co., CA. at the time of his death. He was a member of the California Delagation to the Democratic National Convention in 1884.
The three children of John W. O. BRECKINRIDGE and Louise TEVIS were - Loyd Tevis, John Cabell, and Florence Louise.