There was no “war emergency” that Lincoln faced at Fort Sumter. The US Constitution explicitly states that only Congress may declare war, with four US Supreme Court Justices holding in 1862 that a President’s authority to suppress an insurrection “is not tantamount to the power of initiating a legal state of war, and that civil war does not validly begin with an executive declaration.”
US Senator Thomas Clingman of North Carolina rightly prophesied on March 19, 1861:
“The Republicans intend . . . as soon as they collect the force to have war, to begin; and then call Congress suddenly together and say, “the honor of the country is concerned; the flag is insulted. You must come up and vote men and money.”
Lincoln intentionally bypassed Congress.
America’s 1861 Revolution
“The reaction of the Lincoln administration to the war emergency produced many unusual situations. Governmental norms were abandoned. War powers overbore the rule of law, and extra-legal procedures were initiated. Well-known distinctions of government were obscured. The line was blurred between State and federal functions, between executive, legislative, and judicial authority, and between civil and military spheres. Probably no president, not even Wilson, nor Roosevelt, carried the presidential power, independently of Congress, as far as did Lincoln. He began his administration by taking to himself the virtual declaration of the existence of a state of war, for his proclamation of insurrection (April 15, 1861) started the war regime as truly as if a declaration of war had been passed by Congress.
In issuing this proclamation Lincoln committed the government to a definite theory of the nature of the war (he commenced, but] it may be noted that in strict theory the [United States] government declined to regard the struggle as analogous to a regular war between independent nations. The American Confederacy . . . was deemed a pretender, an unsuccessful rival, and a usurper. Instead of the struggle being regarded as a clash between governments, the Southern effort was denounced as an insurrection conducted by combinations of individuals against their constituted authorities.
In contrast to this, the Southern view was analogous to that of the [British] Americans in the Revolution . . . that the Confederate States was an independent nation conducting war and entitled to the respect due a people fighting off an invader.
Lincoln’s view of his own war powers was most expansive. He believed that in time of war constitutional restraints did not fully apply, but that so far as they did apply, they restrained the Congress more than the President.”
(The Civil War and Reconstruction. J.G. Randall. D.C. Heath and Company, 1937, pp. 382-383; 385)