Final answer:
President Lincoln decided to maintain and resupply Fort Sumter to assert federal authority.
Step-by-step explanation:
President Lincoln had several options regarding Fort Sumter in early April 1861. He could evacuate the fort to avoid further conflict, seek diplomatic negotiations with the Confederate states, maintain and resupply Fort Sumter to assert federal authority, or hand over Fort Sumter to Confederate forces to prevent a prolonged conflict. Initially, Lincoln was leaning towards evacuation or diplomatic negotiations. However, considering Northern public opinion and the recommendation from U.S. General-in-Chief Winfield Scott, Lincoln decided to maintain and resupply Fort Sumter in the least aggressive way possible.