Let's clear up a common misconception. Carpenters work with wood, but not everybody who works with wood has been called a carpenter.

In the past, carpenters were woodworkers who used nails to join pieces of wood. They were not to be confused with joiners, woodworkers who joined wood with adhesive. 

In fact, when the first guilds started in medieval England, carpenters and joiners belonged to separate groups. They were professional rivals. The Worshipful Company of Carpenters (motto: "Honour God") ranks 26th in the order of precedence of English Livery Companies. It has existed since 1271. The Worshipful Company of Joiners and Sealers (motto: "Join Loyalty with Liberty"), by contrast, ranks 41st in teh order of precedence and has been around since 1375.

The distinction between joiners and carpenters started to break down during the expansion of trades unionism in the 19th century. As joiners and carpenters decided that their economic interests were more pressing than their professional rivalry, they joined together in organizations like the Brotherhood of Carpenters and Joiners, the first nationwide woodworking union in the United States.

Oddly enough, Peter McGuire, the founder of that union, was instrumental in the1894 passage of the Labor Day holiday. His fans still call him the "Father of Labor Day" because he arranged the first Labor Day parade, in 1892 in New York City.