Henry R. Harmer, a signatory of the exclusive "Roll of Distinguished Philatelists", founded the company that bears his name in England in 1918. In 1940, the Harmer firm opened its New York auction gallery and quickly ascended to the top ranks of philatelic auction houses in the United States.
In 1946, H.R. Harmer Inc. of New York was selected to sell the late President Franklin Delano Roosevelt’s stamp collection. This represented one of the first of many important landmark auctions to be conducted by the firm. In the ensuing decades, the firm was chosen again and again to sell many of the finest stamp collections ever formed, including the most valuable philatelic collection sold at any U.S. auction - the famed Louise Boyd Dale and Alfred F. Lichtenstein collections - through a series of 25 sales beginning in 1968 and ending in May of 2004.
Other important collections auctioned through H.R. Harmer include those formed by Alfred H. Caspary, William Moody, Sir Henry Tucker, Maurice Burrus Hawaii, Adolphe Menjou, Sandra Ilene West, Paul Beaver, Caesar Cone, Consul Weinberger, Erwin Griswold, Sidney Hessel, Arther Hetherington, Richard Canman, Sigmund Adler, Dr. James A. Matejka, Edward M. Gilbert and the Louis K. Robbins estate. Harmer has also offered many valuable properties and world renowned rarities including the Princeton University Block of Four of the Inverted U.S. 24¢ Airpost and the Charnley and Whelan find of U.S. St. Louis Postmaster Provisional issues.