the closed shop form of union security means that the
Closed shop A pre-entry closed shop (or simply closed shop) is a form of union security agreement under which the employer agrees to hire union members only, and employees must remain members of the union at all times in order to remain employed. This is different from a post-entry closed shop (US: union shop), which is an agreement requiring all employees to join the union if they are not already members.[1] In a union shop, the union must accept as a member any person hired by the employer.[2]
Triangle Shirtwaist Factory fire Because the owners had locked the doors to the stairwells and exits – a then-common practice to prevent workers from taking unauthorized breaks and to reduce theft[8] – many of the workers who could not escape from the burning building jumped from the high windows. The fire led to legislation requiring improved factory safety standards and helped spur the growth of the International Ladies' Garment Workers' Union (ILGWU), which fought for better working conditions for sweatshop workers.