Final answer:
The southern states initially lacked the military power to capture certain Union military installations such as Fort Sumter, which was a significant strategic point. Limited industrial capacity and the strategic decision of border states not to secede hindered the Confederacy. Meanwhile, the Union faced challenges in terms of conquering and pacifying a large and hostile territory, despite having more resources and manpower.
Step-by-step explanation:
During the early stages of the American Civil War, the southern states did not have sufficient military power to overtake certain Union military installations that were critical for the North's strategic position. Notably, Fort Sumter in Charleston, South Carolina became a focal point of tension. When Lincoln took office, he found that Fort Sumter was in dire need of supplies, and any attempt to resupply it would provoke Confederate hostilities. The inevitable conflict materialized when Confederate General P. G. T. Beauregard initiated an attack on Fort Sumter on April 12, 1861, after Lincoln's resupply efforts, marking the official outbreak of the war. Furthermore, the southern call for troops and Lincoln's response with a call for 75,000 volunteers intensified the conflict and underscored the determination of both sides.
The Confederacy was facing challenges beyond military power, including the need for the industrial resources and personnel from the states within the Union. The importance of such states was highlighted by the fact that they "contained most of the South's resources for waging war; more than half its [white] population...three-quarters of its industrial capacity, half its horses and mules, [and] three-fifths of its livestock and food crops." This industrial capacity and potential manpower were essential elements the Confederacy hoped to access by convincing the border states to secede. Despite these ambitions, Delaware, Maryland, Kentucky, and Missouri chose not to secede, depriving the Confederacy of critical resources.
The Confederate advantages lay in their knowledge of the terrain, the defensive nature of their strategy, and the skilled leadership many of whom were trained at West Point. The confederacy controlled a vast territory and was poised for a war of attrition, where their main objective was to outlast Union forces. On the other hand, the Union, with Lincoln's goal to restore it completely, faced a much more daunting challenge requiring a complete military conquest and eventual pacification of the Southern states, testing the limits of the North's superior resources and larger population.