In the United Airlines, Inc. v. McDonald case of 1976, the U.S Supreme Court ruled in favor of a group of flight attendants who sought to challenge their employer's policy on marriage. The initial class action lawsuit was filed by Mary Sprogis against United Airlines for its no-marriage rule that applied only to female flight attendants and not male employees or other female employees within the company. However, when this suit was settled out-of-court before certification as a class action could be decided upon, Carolyn McCrory McDonald moved to intervene so she could appeal denial of class certification which had been denied due to untimeliness under Rule 23(c). The District Court rejected her motion stating it was too late and this decision was upheld by the Seventh Circuit Court of Appeals. However, when brought before the Supreme Court they reversed these decisions ruling that timeliness should be measured from date notice is received about denial for class certification rather than from commencement of litigation itself. This meant McDonald’s intervention wasn’t deemed tardy and thus allowed her claim challenging discriminatory practices at United Airlines to proceed as a representative legal action.

In the dissenting opinion for United Airlines, Inc. v. McDonald, Justice William H. Rehnquist argued that the majority had incorrectly interpreted Rule 23 of the Federal Rules of Civil Procedure by allowing a nonnamed class member to intervene in a suit after judgment has been rendered and appeal time expired. He contended that this interpretation was inconsistent with both precedent and legislative intent behind Rule 23 as it would allow any potential plaintiff to sit back and wait until final resolution before deciding whether or not to join litigation - an approach he believed could lead to inefficiency in legal proceedings and potentially unfair outcomes for defendants who may face additional claims long after they thought litigation was concluded.