Final answer:
The primary goal of the Republican Party at its formation was to keep slavery out of the territories in the United States.
Step-by-step explanation:
The primary goal of the Republican Party when it formed was to keep slavery out of the territories. The party aimed to prevent the spread of slavery into the western territories of the United States.
This goal was in opposition to the interests of southern leaders who wanted to ensure that slavery would be allowed to expand into these territories.