California Proposition 18 was on the November 4, 1958 California ballot measure as an initiated constitutional amendment. This measure is more commonly referred as the "right to work" law and would have added a new provision, Section 1-A to Article 1 of the State Constitution. The amendment would “prohibit employers and employee organizations from entering into collective bargaining or other agreements which establish membership in a labor organization, or payment of dues or charges of any kind, as a condition of employment or continued employment.” That is, making union membership voluntary, rather than compulsory, for employment.