Final answer:
The Border States were important during the Civil War due to their strategic location and resources. President Lincoln took steps to keep these states in the Union by promoting gradual compensated emancipation.
Step-by-step explanation:
The Border States were important during the Civil War because they were located geographically between the North and the South and held key resources that both sides needed. Maryland, Missouri, Kentucky, and Delaware, known as the Border States, were significant because they had a large military manpower, manufacturing capacity, and supply of horses and mules.
President Lincoln took steps to keep the Border States loyal to the Union by pursuing a policy of gradual compensated emancipation, which aimed to abolish slavery in these states and serve as a model for reuniting the rebelling states.