Lincoln took executive control of the war and shaped the Union military strategy. He responded to the unprecedented political and military crisis as commander-in-chief by exercising unprecedented authority. He expanded his war powers, imposed a blockade on Confederate ports, disbursed funds before appropriation by Congress, suspended habeas corpus, and arrested and imprisoned thousands of suspected Confederate sympathizers. Lincoln gained the support of Congress and the northern public for these actions. Lincoln also had to reinforce Union sympathies in the border slave states and keep the war from becoming an international conflict.