Warren Handel Cudworth was born to Warren and Angeline Cooper Brown Cudworth in Lowell, Massachusetts, in 1825. He had one older sister, Angeline Mozart Cudworth. They were raised by their mother, after their father died in 1827. Warren was encouraged to sing and play the organ, and at age 16 was employed at the Lowell Unitarian Church as an organist. Cudworth attended Phillips Andover Academy and graduated from Harvard Divinity School in 1851. He was ordained in 1852 and helped establish a Unitarian church in East Boston. His influence was felt outside of the church; he was active on the committee for public schools and organized aid to the sick and the poor. In 1861, with the fall of Fort Sumter, Cudworth left his church and became a chaplain for the First Massachusetts Regiment, Cos. F and S. He published an account of his experiences in the Civil War in 1865, entitled History of the 1st Regiment (Massachusetts Infantry).
After the war, Cudworth was welcomed back by his church in East Boston. With growing numbers of parishioners, he helped to raise the funds to build a larger church in 1868. In 1880 he embarked on a trip around the world with two generous church members, Mr. and Mrs. Bernard, who paid for the trip. On Thanksgiving Day, November 29, 1883, Cudworth died of a stroke, as he was leading his church in prayer.