What was the most significant land-related outcome of the Treaty of Guadalupe Hidalgo?

The Treaty of Guadalupe Hidalgo ended the Mexican-American War in 1848. Mexico ceded a vast territory to the United States, including present-day California and much of the Southwest—over 500,000 square miles in total. Therefore, the most significant land-related outcome was that the US acquired over 500,000 square miles of land.

AI-written and checked against the verified answer.