What was a key problem regarding Texas' admission to the United States?

Texas' admission to the United States was significantly contentious due to its status as a slave state. When Texas won independence from Mexico in 1836, it was established as a slaveholding republic. The United States was grappling with divisive issues related to slavery, and admitting Texas as a slave state would exacerbate tensions between free and slave states.

This was a pivotal concern during the 1840s as the nation was trying to maintain a balance of power in Congress between free and slave states, particularly following the Missouri Compromise of 1820. The addition of Texas, with its large territory and the potential for dividing the nation further along sectional lines, led to substantial debate and conflict within the U.S., ultimately contributing to the sectional tensions that preceded the Civil War.

Addressing the other factors provided, while Texas may have had various governance challenges, population issues were not the primary consideration in its admission. Texas was not recognized as a former colony in the same context as other territories, and by the time of statehood, border issues with Spain had largely been resolved, particularly after the Adams-Onís Treaty of 1819. Hence, the concern over it being admitted as a slave state stands out as a central issue during this period