Greenwood, Isaac, Jr. (1730-1803), Boston.
Hagger, Benjamin K. (c.1769-1834), Boston and Baltimore; also made surveying instruments.
Halsy, James, II (1695-1767), Boston; also made surveying instruments.
Halsy, John (fl. 1700), Boston.
Ham, James (fl. 1754-1764), New York and Philadelphia.
Ham, James, Jr. (fl. 1780), Philadelphia.
Hamlin, William (1772-1869), Providence, R.I.; also made nautical and astronomical instruments.
Heisely, Frederick (1759-1839), Frederick, Md., and Lancaster, Harrisburg, and Pittsburgh, Pa.; also made clocks and surveying instruments.
Heisely, George (1789-1880), Harrisburg, Pa.; also made clocks.
Hinton, William (fl. 1772), New York.