- Hayner Distilling Co.2
- Heeren Bros. & Co.1
- Helena Mining and Reduction Company1
- Helena and Frisco Mining Company1
- Henderson-Ames Company1
- Hendrie & Bolthoff Mfg. and Supply Co.1
- Hennessy Company1
- Henry & Andrews1
- Henry & Co.1
- Henry Hearne1
- Henry Pettes & Co.1
- Henry S. Zook1
- Henry Seibert & Bros.1
- Henry W. Parker1
- Herald Publishing Co.1
- Hermon W. Ladd Company1
- Herzog Iron Works1
- Hettrick Bros. Company1
- Hettrick Mfg. Co.1
- Hibbard, Spencer, Bartlett & Co.3
- Hill & Wright1
- Hinckley & Egery Iron Company2
- Hincks & Johnson1
- Hires & Co.1
- Hirschberg Bros. & Hollander1
- Hirth-Kraus Company1
- Hoffman Corr MF'G Co.1
- Hoffman House1
- Hoffman, Corkran & Co.1
- Hogan & Son, Agents1
- Holbrook, Merrill & Stetson1
- Holyoke Belting Co.1
- Homer Ramsdell & Co.2
- Hopper, McGaw & Co.1
- Hosford & Ketcham1
- Hotel Alcazar1
- Hotel Boyer1
- Hotel Gazette1
- Hotel Hermitage1
- Hotel Jefferson1
- Hotel Keplinger1
- Hotel Lafayette1
- Hotel Norris1
- Hotel Royal1
- Hotel St. Regis1
- Hotel Walton1
- Hotel Westminster1
- Howard Hotel1
- Howard National Bank of Boston1
- Howard Sanger & Co.1
- Howell & Saxtan1
- Huff Bros. Lumber & Planing Mill Co.1
- Huntington, Hopkins & Co.1
- Husted Milling Co.1
- Huttig Sash & Door Co.1
- Hutzler Brothers1
- Hygeia Hotel1
- I. B. Williams & Sons3
- I. Newman & Sons2
- I. P. Thomas & Son Company1