Question: The power of declaring war resides, according to the Constitution, in Congress. Yet Lincoln essentially declared war by ordering the blockade of Southern ports. How did the Supreme Court react to that? Did that start us on the road to the "imperial presidency," which Congress finally tried to stop with the War Powers Resolution in the post-Vietnam era?
Farber: Lincoln's actions were actually fairly easy to justify under the Constitution. When the Constitution was being framed, the drafters deliberately gave Congress the power to declare war (rather than to "make" war). They wanted the president to be able to act on his own if the country was attacked. In Lincoln's case, a third of the country was in hostile hands, and a U.S. fort had been attacked and taken by hostile troops. Rather than acting like an imperial president, he then turned to Congress for approval. Ironically, his actions came closer to complying with the standards of the War Powers Resolution, over a century before it was passed, than most presidents have done in the modern era.
http://www.press.uchicago.edu/Misc/Chicago/237931in.html
The very last act of the Senate on March 28, 1861, was to check with the President to see whether he had anything to tell them before they adjorned.
Mr. Powell, from the committee appointed to wait on the President of the United States and notify him that unless he has some further communication to make, the Senate is ready to adjourn, reported that the committee had waited on the President, and been informed by him that he had no further communication to make to the Senate.
On March 29, Lincoln ordered Welles and Cameron to prepare the relief expedition to Sumter. He waited for the Senate to adjorn before he took an action bound to end in a shooting war.
From the Cincinnati Enquirer as reported in the Memphis Daily Appeal of March 27, 1981:
The New York and all Eastern Republicans are getting clamorous for an extra session. They now admit that, critical and extraordinary as the condition of the country is, the President is without power to to take any effectual step toward its relief. He can effect no fixed and decisive policy toward the seceding States, because no laws give him authority to carry it into effect.
He cannot enforce the laws, because no power has been put at his command for that purpose. He cannot close the ports which refuse to pay Federal duties, nor has he the authority to enforce payment except through the local authorities. These, moreover, are the least of the difficulties which embarrass the action of the Government. This loan is called for, but there is no prospect of revenue to render it safe. The seceded States invite imports under the tariff of 1857, at least ten per cent. lower than that which the Federal Government has just adopted. As a matter of course, foreign trade will seek southern ports, because it will be driven there by the Morrill tariff. It has been stated that Secretary Chase has been heard to say that the tariff bill must be repealed.