American historian, born in Providence, RI, on the 12th of April 1821. He graduated at Brown University in 1841, studied at Harvard Law School, and was admitted to the bar in 1845. In 1852, in 1861, and again in 1862, he was elected lieutenant-governor of Rhode Island. He commanded, for a short time, a battery of artillery on the outbreak of the Civil War. From December 1, 1862, to March 3, 1863, he was a member of the United States Senate in the place of J. F. Simmons, who had resigned. Mr. Arnold published a valuable History of the State of Rhode Island and Providence Plantations (1859). He died on the 12th of February 1880.
