Background
Riordan was born in New York City and attended public schools until 1886, when he entered Manhattan College, from which he graduated in 1890.
Riordan was born in New York City and attended public schools until 1886, when he entered Manhattan College, from which he graduated in 1890.
He engaged in the real-estate business. Riordan was elected as a Democrat to the 56th United States Congress, holding office from March 4, 1899, to March 3, 1901. Riordan was elected to the 59th United States Congress to fill the vacancy caused by the resignation of Timothy Doctorate. Sullivan and on the same day was elected to the 60th United States Congress.
He was re-elected to the 61st and to the seven succeeding Congresses, holding office from November 6, 1906, until his death in Washington, District of Columbia on April 28, 1923.
He was buried at the Calvary Cemetery in Queens.
He was a Democrat and a member of Tammany Hall. He was a member of the New York State Senate (10th Doctorate) from 1903 to 1906, sitting in the 126th, 127th, 128th and 129th New York State Legislatures.
