In the United States v. California and Oregon Land Company case of 1903, the Supreme Court ruled on a dispute over land ownership in California. The U.S government claimed that certain lands were part of public domain while the defendant company asserted they had acquired valid title to these lands through Mexican grants confirmed by an Act of Congress in 1866. The court held that under international law, when territory is transferred from one sovereign to another, pre-existing private property rights are generally respected and preserved unless explicitly extinguished by legislative action. Therefore, it was determined that if there was any ambiguity about whether or not these titles were intended to be confirmed by Congress's act, such doubt should be resolved in favor of those claiming under them. As a result, the Supreme Court upheld lower courts' decisions confirming California and Oregon Land Company’s claim to the disputed properties.

In the dissenting opinion for United States v. California and Oregon Land Company, it was argued that the majority's decision to nullify land patents granted by Congress decades earlier set a dangerous precedent. The dissenting justices contended that this ruling undermined property rights and created uncertainty in land ownership, as any title could potentially be revoked if later deemed improperly granted. They also disagreed with the majority's interpretation of Congressional intent behind these grants, arguing instead that they were meant to encourage settlement and development of western lands rather than being contingent on specific conditions or uses. Furthermore, they expressed concern over potential negative impacts on economic growth due to increased insecurity in real estate transactions resulting from this decision.