Final answer:
Virginia refused President Lincoln's request for volunteers to help fight the insurrection against federal property because they believed it was the federal government's responsibility, not the state's.
Step-by-step explanation:
Virginia refused President Lincoln's request for volunteers to help fight the insurrection against federal property because (a) Virginia believed it was the federal government's responsibility, not the state's. Virginia favored a weak central government and supported the sovereignty of individual states. They resented President Lincoln's efforts to conscript troops and requisition necessary resources. Additionally, Virginia doubted the credibility of Lincoln's request and the motives behind it.