Tensile strength is defined as a stress, which is measured as force per unit area. For some non-homogeneous materials (or for assembled components) it can be reported just as a force or as a force per unit width.
Answer Wiki. The practice of organizing to aggregate individuals' influence for economic reasons probably began with European craft guilds, although the master craftsmen were actually employers and capitalists. Trade unions or labor unions originated in England in the 1700s, but were outlawed until the 1800s.
From its inception in 1905, the Industrial Workers of the World criticized existing craft unions for creating a labor aristocracy. Eugene V. Debs wrote that seasoned old unionists could see that working people couldn't win with the labor movement they had.