- Pioneer Broom Co.2
- Pioneer Broom Company Inc.2
- Pioneer Paper Stock Co.1
- Pitkin & Brooks1
- Pittsburg and Philadelphia Oil and Refining Company1
- Pittsburgh Dry Goods Company3
- Plankinton House1
- Planters Hotel2
- Plaza Hotel1
- Pleuger & Henger Mfg. Co.1
- Plimpton Cowan & Co.1
- Plumb & Winton Co.1
- Plumer, Chandler & Co.3
- Plunkett-Jarrell Grocer Co.2
- Poland Mineral Springs3
- Poland Spring1
- Poland Spring House1
- Pollock & Van Wagenen1
- Poole & Hunt1
- Portsmouth Coal Pockets1
- Pratt & Cady Co.1
- Pratt & Co.1
- Pratt Food Company1
- Price & Weatherhead1
- Providence Machine Company1
- Providence Steam and Gas Pipe Co.1
- Providence Tool Company3
- Providence Washington Insurance Company1
- Providence Worsted Mills1
- Pruyn, Vosburgh & Co.1
- Puck Building Account1
- Putnam & Brooks1
- Putnam Machine Company1
- Quaker City Cold Storage & Warehouse Co.1
- Quincy1
- R. A. Butler1
- R. C. Reynolds Co.1
- R. E. Tongue & Bros.1
- R. H. White & Co.6
- R. H. Wolff & Co., Limited1
- R. J. Allen, Son & Co.1
- R. Longman's Sons1
- R. M. Bishop & Co.1
- R. M. Van Sickler & Forby1
- R. McMichael1
- R. S. McNeill1
- R. S. Newbold & Son Co.1
- R. S. Weston Coal Co.1
- R. S. Weston Truck & Coal Co.1
- R. W. Soule1
- R.G. Dun & Co.1
- R.L. Polk & Co.1
- Racine Mangle Co.1
- Radford Architectural Company1
- Ramsey County1
- Raphael Weill & Co.1
- Rathbone, Sard & Co.3
- Raynolds, Devoe and Pratt2
- Rea & Co.1
- Reed & Hewlett1