The American Waltham Watch Company can trace it's roots to 1851 when a company was started to manufacture pocket watches for the mass market. Having to first devise, develop, and then manufacture the machinery necessary to produce the components of a watch, such that each part should be interchangeable in every watch proved more difficult than had been anticipated. Consequently the company went through several name changes, ownership changes, and near bankruptcy's before the first true mass produced watch, the model 1857 came to market. These were initially sold with model names such as P S Bartlett but soon the brand became know as "The American Watch Co". After several later name changes the company became known generically as Waltham Watch Co.  During the company's lifetime it produced over 35,000,000 watches including wristwatches from about 1915. So good were these watches that many hundreds of thousands are still giving reliable service today.