Claim: Four free states, including the State of California, the most populated subnational entity in North America, ratified the US Constitution or was admitted to the Union from 1850 to 1861.
Evidence: California, officially the State of California, is a state in the Pacific Region of the United States of America. California is also the most populated subnational entity in North America, and has its state capital in Sacramento. On September 9, 1850, as part of the Compromise of 1850, California became a free state and September 9 a state holiday. The Compromise of 1850 was a package of five separate bills passed by the United States Congress in September 1850 that defused a political confrontation between slave and free states on the status of territories acquired in the Mexican–American War. California was admitted as a free state, while the remaining portions of the Mexican Cession were organized into New Mexico Territory and Utah Territory. On December 29, 1845, the Republic of Texas was annexed to the United States and became the 28th state. Congress also faced the issue of Utah, which like California and New Mexico, had been ceded by Mexico.