In the case of Sosna v. Iowa, the Supreme Court ruled in favor of an Iowa statute that required a one-year residency before filing for divorce within the state. The plaintiff, Carol Sosna, moved to Iowa and filed for divorce less than a year later; her case was dismissed due to this statute. She claimed it violated her right to travel under the Privileges and Immunities Clause as well as Equal Protection Clause of the Fourteenth Amendment. However, in 1974, with a majority vote of 8-1, SCOTUS upheld that states have legitimate interests in requiring certain periods of residency before granting divorces because they are essentially creating new status relationships between two people who were previously married under another jurisdiction's laws.

In the dissenting opinion for SOSNA v. IOWA et al., Justice Brennan, joined by Justices Douglas and Marshall, argued that Iowa's one-year residency requirement for divorce proceedings was unconstitutional. They contended that it violated the Equal Protection Clause of the Fourteenth Amendment because it discriminated against recently arrived residents without a compelling state interest to justify such discrimination. The dissenters believed that while states have an interest in preventing "divorce tourism," this could be achieved through less restrictive means than a blanket one-year waiting period. Furthermore, they pointed out inconsistencies in how Iowa applied its residency requirements across different legal contexts which undermined their argument about maintaining integrity of their courts system. Lastly, they disagreed with majority’s view on mootness issue arguing plaintiff’s case should not be considered moot just because she fulfilled residency requirement during litigation process as her initial injury remained unaddressed.