Final answer:
Texas is one state created out of the Mexican Cession. It declared its independence from Mexico in 1836 and became the Republic of Texas.
Step-by-step explanation:
One state created out of the Mexican Cession was Texas. In 1836, Texas declared its independence from Mexico and established itself as the Republic of Texas. This independent state of Texas existed until 1845, when it was admitted into the United States as the 28th state.