What was one major legislative act that affected Texas in 1848?

The major legislative act that significantly affected Texas in 1848 was the Treaty of Guadalupe Hidalgo. This treaty formally ended the Mexican-American War and led to Mexico ceding a large portion of its territory to the United States, including present-day Texas, California, Arizona, New Mexico, and parts of other states. The impact of this treaty on Texas was profound, as it solidified the state's boundaries and contributed to the expansion of U.S. territory.

While the Wilmot Proviso, aimed at banning slavery in the newly acquired territories, was a contentious proposal and influenced the national debate on slavery, it did not pass and therefore did not become law. The Compromise of 1850, which sought to address the issues arising from these territorial gains, occurred after the Treaty of Guadalupe Hidalgo and was part of the broader congressional response to the territorial expansion. The Morrill Act, passed later in 1862, related to land-grant colleges and is not directly relevant to the 1848 timeframe.

Thus, the Treaty of Guadalupe Hidalgo stands as the pivotal legislative act of 1848 affecting Texas, defining its current geographical and political landscape.