Final answer:
The concept of people deciding for themselves about allowing slavery is known as popular sovereignty, which was particularly relevant leading up to the American Civil War. This principle allowed the residents of territories to decide the legality of slavery within their borders and reflects the historical significance of civic engagement and the fight for civil liberties.
Step-by-step explanation:
People or civilians deciding for themselves whether to allow slavery is an example of popular sovereignty. This concept refers to the idea that the residents of territories could decide whether their land should be slave or free. It was a significant point of contention in U.S. history, particularly leading up to and during the Civil War.
Options like the Wilmot Proviso and the Free Soil solution were different political responses to the spread of slavery. The concept of popular sovereignty arose in the mid-19th century as a compromise to address the divisive issue of slavery in newly acquired territories, ultimately allowing the residents of the territories to vote on the legality of slavery within their borders.
The history of the United States is filled with instances where civic engagement and actions by ordinary people, such as abolitionists and civil rights activists, have challenged and changed government policies, including the abolition of slavery. Both the fight against slavery and the civil rights movement highlight the ongoing struggle and importance of civil liberties in American history.