Which of the following was a goal of the 'Free Soil Party'?

The goal of the Free Soil Party was primarily to oppose slavery in newly acquired territories, particularly those added after the Mexican-American War. Founded in 1848, the party emerged in response to the debate on whether the newly acquired lands from Mexico should permit slavery. While the party included members with varying views on race and equality, its central focus was on preventing the extension of slavery into these new western lands, framing the issue around the notion of "free soil" for free men. This position was tied to a broader belief that the presence of slavery would undermine opportunities for white settlers and workers in the West, as they sought to create a labor market that was free from the competition of slave labor.

The other options reflect different political goals or concerns that did not align with the primary mission of the Free Soil Party. For example, while advocating for higher tariffs or expanding the railroad network were issues of the time, they were not core objectives of the Free Soil Party. Similarly, the call for full equality for former slaves was a more radical stance that was not part of the main agenda of the party. Thus, the focus on opposing slavery in newly acquired land remains the defining aim of the Free Soil Party.