What was a direct outcome of Texas being admitted as a slave state?

The admission of Texas as a slave state had significant implications for sectional tensions in the United States. It exacerbated the already existing divide between the northern states, which were primarily free states, and the southern states, where slavery was a fundamental institution. This event was pivotal in heightening the discord between pro-slavery advocates and abolitionists, leading to intensified debates and conflicts over the expansion of slavery into new territories acquired through events such as the Mexican-American War.

The incorporation of Texas into the Union further fueled fears in the North that the institution of slavery would spread, prompting calls for measures such as the Wilmot Proviso, which sought to ban slavery in territories acquired from Mexico. The resulting contentious political climate eventually contributed to the formation of the Republican Party, which opposed the expansion of slavery, and set the stage for the Civil War.

The other options do not capture the essence of the direct impacts of Texas's admission. It did not lead to an increase in free states, nor did it end the debate over expansion; rather, it ignited further discussions. Additionally, relations with Mexico worsened following the annexation of Texas, culminating in military conflict rather than improvement. Therefore, the choice highlighting the reinforcement of sectional tensions accurately reflects the historical consequences of Texas