Prior to the 1972 amendment of the Civil Rights Act, the Act did not present itself as the best legal basis upon which to sue a union on behalf of private-sector employees whose religious rights had been violated. Such litigants more commonly used the First Amendment's guarantee of the free exercise of religion in an effort to get unions to accommodate their religious beliefs. These efforts were largely unsuccessful.

Two typical cases are Gray v. Gulf, Mobile & Ohio Railroad Co. 22and Linscott v. Millers Falls Co.23 In Gray, a Seventh Day Adventist refused to join a union because of his religious convictions. This constituted a violation of a union security clause requiring employees to become union members within 60 days of employment. This individual rejected the union's offer to permit him to pay an agency fee and forego formal union membership.

The railroad terminated Gray as called for in the collective bargaining agreement. Gray sued on several Constitutional grounds, including the First Amendment's free exercise clause.24 Both the trial and appellate courts ruled against Gray.

Likewise in Linscott, a Seventh Day Adventist refused to join the union as required by a union security clause due to her religious convictions, offering instead to pay an amount equivalent to her union dues and initiation fees to a non-religious charity. The union refused, Linscott was discharged, and she sued on First Amendment grounds. Linscott lost at both the trial and appellate levels,25 with the appellate court concluding that the government's interest in maintaining a peaceful labor relations climate outweighed the burden imposed on Linscott to protect her religious sensibilities.26