[rustbucket]

[me]: Taney thought so.

[you]: No he didn't

Carl Brent Swisher, "Roger B. Taney," The MacMillan Company, 1936 at page 551 (emphasis mine):

"An audience of some two thousand people assembled on the following day to witness the outcome of the struggle between the Chief Justice and the military authorities. Leaving the Campbell home in the company of his grandson, Taney remarked that he might be imprisoned in Fort McHenry before night, but he was going to court to do his duty. As he took his place he announced that he acted alone rather than with Judge Giles because of the fact that he was sitting not as a member of the circuit court, but as Chief Justice of the United States. "One reason for the distinction, undoubtedly, was the belief that it would lent added weight to the decision."

That is consistent with newspaper accounts. From the Baltimore Sun, May 29, 1861:

"Chief Justice Taney, upon taking his seat on the bench, said that he desired to state that his associate, Judge Giles, of the Circuit Court, was present with him yesterday by his invitation, because he desired to avail himself of his counsel and advice in so important a case. The writ of habeas corpus was ordered by him as Chief Justice of the Supreme Court of the United States, consequently Judge Giles could not act with him in the case."

Then there is the matter of Taney posting the decision as an "at Chambers" decision. Means it is a decision of a Supreme Court justice. Here's what he posted:

"Decision. Ex parte John Merryman. Before the Chief Justice of the Supreme Court of the United States at Chambers."

Some time ago I checked with poster Congressman Billy Bob, who has argued many cases before the Supreme Court. He said that his first Supreme Court win came from a ruling made by a single justice. You don't have to have the full court.

[Non-Sequitur]

Then why did Taney hear the case at the Circuit Court bench for the district of Maryland if he was hearing the case for the entire court? Why did he file his decision with the Circuit Court and not the Supreme Court? Why haven't you read the decision? The answers for the first two are because Taney heard the case in his position as head of the Circuit Court for the District of Maryland. I don't know the answer to the third question.

He said that his first Supreme Court win came from a ruling made by a single justice. You don't have to have the full court.

I would be very interested in learning the identity of a single case decided by a single justice on behalf of the entire court. I know that justices are responsible for a federal circuit and that they can issue stays in that circuit or issue decisions for that circuit, but I have never heard of a single judge issuing a decision. According to the Judiciary Act of 1789 a quorum is required.