Whitehorn was born in the
Principality of Romania in 1879. After the death of his mother, when he was about ten years old he emigrated together with his three years older brother to the
United States. They lived in
New York City where Joseph became a
paperboy, and some years later a clerk in a clothing factory. While working during the day, he attended the evening course at
New York University School of Law, graduated in 1904, was admitted to the bar, and began the practice of law in
Manhattan. The next year he moved to
Brooklyn. Whitehorn was a member of the Socialist Party of America. In November 1916, he was elected to the New York State Assembly (Kings Co., 21st D.), defeating the incumbent Democrat
Isaac Mendelsohn. Whitehorn was a member of the
140th New York State Legislature in 1917. Mendelsohn contested Whitehorn's election, but the Assembly decided in favor of Whitehorn. In November 1917, after re-apportionment, he was re-elected to the Assembly in the 14th District of Kings County, and was a member of the
141st New York State Legislature in 1918. The
Citizens Union called Whitehorn an "able and effective" legislator. In November 1918, he ran for Congress in the
3rd District, but was defeated by Republican
John MacCrate who had also won the Democratic primary. In November 1925, Whitehorn ran unsuccessfully for the
New York Supreme Court (2nd D.), polling 17,568 votes. Whitehorn died of a
brain aneurysm on January 23, 1926. He was survived by his wife Sarah and three sons. ==References==