ABBOTT, Horace, manufacturer, born in Sudbury, Massachusetts, 29 July, 1806; died in Baltimore, Maryland, 8 August, 1887. He was early engaged in the manufacture of shafts, cranks, axles, etc., ill Baltimore, and is said to have made the first large steamboat shaft ever forged in this country. In 1850 he built his first rolling mill, which was larger than any before attempted in the United States. A second mill, built in 1857, contained a pair of ten-foot rolls, which were described as being the longest plate rolls ever made in America. In 1858 a third mill was erected, and in 1861 a fourth. In these mills the armor-plates for the " Monitor" were made, and subsequently those for nearly all the vessels of the monitor class built on the Atlantic coast, as well as for the "Roanoke," "Agamenticus,"" Monadnock," and other government vessels. In 1865 an association of capitalists purchased the entire works and organized a stock company known as the Abbott Iron Company of Baltimore, and elected Mr. Abbott president.