“Since we’ve never seen a copy of these orders, how do you know they didn’t give him authority to start shooting?”
EXECUTIVE MANSION, WASHINGTON, April 1, 1865.
Lieut. D.D. PORTER will take command of the steamer Powhatan, or any other United States steamer ready for sea, which he may deem best fit for the service to which he has been assigned by confidential instructions of this date.
All officers are commanded to afford him all such facilities as he may deem necessary for getting to sea as soon as possible.
He will select the officers to accompany him.
(Signed) ABRAHAM LINCOLN.
Recommended,
(Signed) WILLIAM H. SEWARD.
EXECUTIVE MANSION, April 1, 1861.
Lieut. D.D. Porter, United States Navy:
SIR: You will proceed to New-York, and with the least possible delay, assume command of any naval steamer available, proceed to Pensacola harbor, and at any cost or risk prevent any expedition from the main land reaching Fort Pickens or Santa Rosa Island.
You will exhibit this order to any naval officer at Pensacola, if you deem it necessary, after you have established yourself within the harbor, and will request cooperation by the entrance of at least one other steamer.
This order, your object and your destination will be communicated to no person whatever until you reach the harbor of Pensacola.
(Signed,) ABRAHAM LINCOLN.
Recommended.
(Signed,) WILLIAM H. SEWARD.
[Enclosure.]
WASHINGTON, EXECUTIVE MANSION, April 1, 1861.
PRESIDENT LINCOLN TO CAPT. MERCER OF THE POWHATTAN
WASHINGTON CITY, April 2, 1861.
[Confidential.]
SIR: Circumstances render it necessary to place in command of your ship (and for a special purpose) an officer who is fully informed and instructed in relation to the wishes of the government, and you will therefore consider yourself detached. But in taking this step, the government does not in the least reflect upon your efficiency and patriotism; on the contrary, have the fullest confidence in your ability to perform any duty required of you.
Hoping soon to be able to give you a better command than the one you now enjoy, and trusting that you will have full confidence in the disposition of the govennnent toward you, I remain, &c.,
(Signed,) ABRAHAM LINCOLN.
Capt. S. MERCER, United States Navy.
A true copy. (Signed,) M.C. MEIGS, Captain of Engineers and Chief Engineer of Col. BROWN’s Expedition
The forth order Porter drafted for Lincoln’s signature concerned relieving Captain Silas Stringham of his duties at the New York Naval Shipyard and had nothing to do with the Pensacola operation.
Yes, Porter had orders to take command of the Ship, but he had other orders besides those, and those we've never seen.
You can get a clue from reading Lincoln's orders to Mercer where he references that Porter has particular instructions.
Also, does that sound like Porter wrote it?