Ever since it was formed in 1883, the group now known as the National Association of Plumbing-Heating-Cooling Contractors has been a force to contend with in industry affairs. Its forerunner, the National Association of Master Plumbers, was especially powerful in the first three decades of this century.
NAMP was established for the primary purpose of forcing manufacturers to "respect" traditional industry trade channels — i.e., to ensure plumbing wares were sold only through the plumbing trade. They were never fully successful in this quest. From the industry’s earliest days, master plumbers raged at manufacturers and suppliers over sales to hardware stores, mail order houses, direct to users, etc.
Nonetheless, in the old days they were influential enough to force quite a few firms into line, or at least into using elaborate subterfuge to sell outside of industry channels. NAMP’s aggressiveness in this regard led to two separate waves of federal antitrust turmoil in the years leading up to both world wars.
NAMP membership reached 10,424 in 1914, about double that of today. This was in an industry with only one-fifth or one-sixth the number of firms as today. Thus, they appear to have represented a third to half of all plumbing firms in business back then. By comparison, it’s estimated that the NAPHCC of 1993 represents no more than one-tenth of its potential market.
NAMP suffered some decline in the ensuing years leading up to the 1920s, mainly due to war and a series of antitrust actions in the period 1914-1917. They reversed that trend in the 1920s, and by 1929 had climbed to what appears to have been their all-time high in membership, 11,670.
