What major issue arose from Texas being admitted as a state?

The admission of Texas as a state significantly contributed to the tensions surrounding slavery in the United States, making it a pivotal issue in the lead-up to the Civil War. Texas was admitted to the Union as a slave state in 1845, which escalated the ongoing conflict between free and slave states. This decision had profound implications, as it disturbed the balance in Congress between slave and free states, potentially leading to increased sectional conflict.

The extension of slavery into Texas was particularly contentious because it not only affected the political landscape but also raised concerns about the expansion of slavery into other territories. The addition of Texas as a slave state intensified debates over the status of new states admitted to the Union and reignited discussions about the future of slavery in America, including the Missouri Compromise and the Compromise of 1850.

The other options do not correctly represent the historical context surrounding Texas's admission to the Union. Texas's admission was not a matter of being a free state or its location relative to the Mason-Dixon line, and it did not directly involve changes in tariffs on cotton. Therefore, recognizing Texas as a slave state is essential to understanding its historical significance and the broader implications for the nation at that time.