Delaney was born in New York City March 19, 1901; attended the public schools in Long Island City, Queens. He graduated from the law department of St. John’s College, Brooklyn, N.Y. LL.B., 1931; was admitted to the bar in 1933 and commenced practice in New York City; assistant district attorney of Queens County from 1936-1944.

Delaney elected as a Democrat to the Seventy-ninth Congress (January 3, 1945-January 3, 1947); unsuccessful candidate for reelection in 1946 to the Eightieth Congress; resumed the practice of law in New York City; elected to the Eighty-first Congress; reelected to the fourteen succeeding Congresses and served from January 3, 1949, until his resignation December 31, 1978; chairman, Select Committee to conduct an investigation and study of the use of chemicals, pesticides, and insecticides in and with respect to food products (Eighty-first and Eighty-second Congresses) in which instance he is notable for adding the 1958 Delaney clause to the 1938 Food, Drugs, and Cosmetic Act to ban carcinogens as food additives, Committee on Rules (Ninety-fifth Congress); was not a candidate for reelection in 1978 to the Ninety-sixth Congress; was a resident of Key Biscayne, Florida, until his death in Tenafly, New Jersey on May 24, 1987; interment in Calvary Cemetery in Queens.