- National Tube Works Company3
- National Union Insurance Company2
- National Warehouse Co. Inc.1
- Neal & Hyde1
- Neidich Process Company1
- Nelson Chesman & Co.1
- Neustadters Bros.1
- New Atlantic Hotel1
- New Avenue Hotel1
- New England Biscuit Co.1
- New England Confectionery Co.1
- New English Hotel1
- New Haven Spring Co.1
- New Home Machine Co.3
- New Home Sewing Machine Co.1
- New Home Sewing-Machine Co.1
- New Jersey Car Spring and Rubber Co.2
- New Jersey Trust and Safe Deposit Company1
- New Jersey Tube Co.1
- New Phoenix Hotel1
- New Tremont1
- New Werner Company1
- New York Architectural Terra Cotta Co.1
- New York Belting & Packing Co., Ltd.2
- New York Hygienic Institute1
- New York Institution for the Blind1
- New York Iron Works1
- New York Oil Cabinet Company2
- Newark Embroidering Works1
- Newburgh Ice Machine and Engine Co.1
- Newburgh Journal1
- Newell Coal & Lumber Company3
- Newman & Capron1
- Newman & Son1
- Niagra Wood Paper Co.1
- Nichols & Cox Lumber Co.1
- Noble Machine Co.1
- Nonotuck Silk Company3
- Northrup Glove M'f'g. Co.1
- Northrup, King & Co.1
- Northwestern Cooperage & Lumber Company1
- Northwestern School Supply Co.1
- Northwestern Terra Cotta Company1
- Northwestern Trunk & Traveling Bag M'f'g Co.1
- Norton Brothers1
- Norwalk Lock Company1
- Norwich Belt Mfg. Co. Inc.1
- Norwich Bleaching, Dying & Printing Company1
- Novelty and Plating Works1
- Noyes & Nutter Mfg. Co.2
- O. D. Goodrich & Co.1
- O. Kendall & Co.1
- Oak Hall2
- Odell Bros.1
- Oehm's Acme Hall2
- Office of Philadelphia Shot Tower1
- Officer & Pusey1
- Old Bridge Tile Co.1
- Olin J. Stephens1
- Oliver Johnson & Co.2