About Denis O'Brien
Lived 1837 – 1909 (aged 72). Denis O'Brien was an American lawyer and judge.
Denis O'Brien (March 13, 1837 – May 18, 1909) was an American lawyer and politician.
Life Denis O'Brien was born on a farm near Ogdensburg, New York on March 13, 1837. He was admitted to the bar in 1861, and commenced practice in Watertown. He was elected Mayor of Watertown in 1872.
He was New York State Attorney General from 1884 to 1887, elected on the Democrat ticket in 1883 and 1885.
He died from appendicitis at his home in Watertown on May 18, 1909.
His son John F. O'Brien also was a judge of the New York Court of Appeals.
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Important facts
People in Denis O'Brien's life
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Contemporaries
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Frequently asked questions
Who was Denis O'Brien?
American judge
When was Denis O'Brien born?
Denis O'Brien was born on 13 March 1837 in Ogdensburg.
When did Denis O'Brien die?
Denis O'Brien died on 18 May 1909 in Watertown.
What was Denis O'Brien's occupation?
Denis O'Brien was a lawyer and judge.
What nationality was Denis O'Brien?
Denis O'Brien was American.
Sources & further reading
· DBpedia: Denis O'Brien (politician)
Cite this page
APA: Biography.guide. (2026). Denis O'Brien. https://biography.guide/denis-o-brien/
MLA: "Denis O'Brien." Biography.guide, https://biography.guide/denis-o-brien/.
Chicago: "Denis O'Brien." Biography.guide. https://biography.guide/denis-o-brien/.
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