Hudson River Monuments
Nicholas O'Brien, Jr. the proprietor of this Marble and Stone Factory located on Water Street was a noted craftsman in Sing Sing at the time. The firm was established in 1852 and the building still stands. The marble industries associated with Hudson communities were noteworthy. By the 1820s sources of building materials were greatly needed for the tremendous growth faced by New York City (a result from the opening of the Erie Canal in 1825). Sing Sing (Prison) was one of the quarries for the supply of "Westchester Marble" before the Civil War.