Civil libertarians are crying foul over the indefinite detention of hundreds of Sept. 11 suspects and plans to try accused terrorists in military tribunals. In defense, some Bush administration loyalists cite another wartime leader who locked up civilians and resorted to army courts, Abraham Lincoln—even though Lincoln faced a radically different situation, and, more important, his civil liberties record stands as a rare blot on his reputation.

In his authoritative Fate of Liberty: Abraham Lincoln and Civil Liberties (1991), Mark Neely has argued that during the Civil War these two policies—summary arrests and military justice—were of a piece. Both stemmed from the emergency of having an armed rebellion in the nation’s midst, and they were viewed as two parts of a single policy. Yet today we think of the policies as separate, if related. So this week I’ll consider Lincoln’s more famous action, his suspension of the privilege of the writ of habeas corpus. Next week, I’ll tackle what at the time was considered the more egregious violation, the use of military tribunals to prosecute civilians.

First a definition: The Latin phrase habeas corpus means “you have the body.” The privilege of the writ of habeas corpus refers to a common-law tradition that establishes a person’s right to appear before a judge before being imprisoned. When a judge issues the writ, he commands a government official to bring a prisoner before the court so he can assess the legality of the prisoner’s detention. When the privilege of the writ is suspended, the prisoner is denied the right to secure such a writ and therefore can be held without trial indefinitely. Habeas corpus is the only common-law tradition enshrined in the Constitution, which also explicitly defines when it can be overridden. Article I, Section 9 of the Constitution says, “The privilege of the writ of habeas corpus shall not be suspended, unless when in cases of rebellion or invasion the public safety may require it.”

Several times during the war, Lincoln or his Cabinet officers issued orders suspending the writ. The first came early in his presidency. Lincoln had been in office for barely a month when Confederate troops attacked the federal garrison at Fort Sumter in April 1861, starting the Civil War. One of his immediate concerns was how to keep an unobstructed route between Washington, D.C., and the North. He worried that if Maryland joined Virginia and seceded from the Union, the nation’s capital would be stranded amid hostile states. On April 19, 20,000 Confederate sympathizers in Baltimore tried to stop Union troops from traveling from one train station to another en route to Washington, causing a riot. So on April 27 Lincoln suspended the habeas corpus privilege on points along the Philadelphia-Washington route. That meant Union generals could arrest and detain without trial anyone in the area who threatened “public safety.”

Controversy followed. The most explosive incident centered on John Merryman, a Marylander arrested for insurrectionary activities. Summarily jailed, Merryman petitioned for a habeas corpus writ, which Chief Justice Roger Taney granted. But the commanding officer at Fort McHenry, where Merryman was held, refused to release the prisoner, citing Lincoln’s edict. With the army loyal to Lincoln, Taney couldn’t enforce his order and railed against the president while Merryman stewed in jail for seven more weeks. After being freed, he was never tried.

The Merryman case and others like it ignited a debate over Lincoln’s actions. Democrats argued they were unconstitutional. Taney noted that Article 1 of the Constitution, where habeas corpus is discussed, deals exclusively with congressional powers, meaning that Congress alone can authorize the privilege’s suspension. Although correct, Taney’s argument framed the debate around a legalistic and secondary issue, that of congressional versus presidential power. It skirted the question of whether the situation warranted a suspension of habeas corpus at all. Thus when in March 1863 Congress passed the Habeas Corpus Act, effectively endorsing Lincoln’s actions, civil libertarians were stripped of their main argument. (Taney also criticized Merryman’s detention, noting that civilians aren’t subject to military justice—an issue I’ll get to next week.)

Where Democrats marshaled constitutional arguments against Lincoln’s order, Republicans replied that in an emergency, only the president could act fast enough to protect the public safety. Lincoln himself took this line in a famous July 4, 1861, speech to Congress. He also, more memorably, used a pragmatic argument. “Are all the laws but one to go unexecuted,” he chided his critics, “and the government itself go to pieces, lest that one be violated?” The phrase has been quoted ever since and even provided the title of a recent apologia by Chief Justice William Rehnquist for wartime suppression of freedoms.

Despite the rhetorical power of Lincoln’s speech, there’s no evidence the government would have gone to pieces. By the time he issued his April 27 order, Union troops had made their way through Baltimore, and it should have been clear that Washington wasn’t going to be fatally isolated. As for dissuading Maryland from seceding, contemporaneous accounts suggest that whatever the administration’s fears, no such move was imminent.

If Lincoln’s Maryland actions were dubious, a wave of arrests the following summer under another habeas corpus suspension was downright indefensible. The wave began after Congress instituted the first-ever military draft in July 1862. Because the draft proved highly unpopular and hard to enforce, Secretary of War Edwin Stanton, at Lincoln’s behest, issued sweeping orders on Aug. 8 suspending habeas corpus nationwide—the first time the writ was suspended beyond a narrowly defined emergency area. Stanton decreed that anyone “engaged, by act, speech, or writing, in discouraging volunteer enlistments, or in any way giving aid and comfort to the enemy, or in any other disloyal practice against the United States” was subject to arrest and trial “before a military commission.”

The exceedingly broad mandate precipitated a civil liberties disaster. It allowed local sheriffs and constables to decide arbitrarily who was loyal or disloyal, without even considering the administration’s main goal of enforcing the draft. At least 350 people were arrested in the following month, an all-time high. Some of the accused had done nothing worse than bad-mouth the president. (That was also true before Aug. 8. On Aug. 6, for example, Union Gen. Henry Halleck arrested one Missourian for saying, “[I] wouldn’t wipe my ass with the stars and stripes.”)

On Sept. 8, the federal official overseeing these arrests decreed that law enforcement agents were enforcing the Aug. 8 orders too stringently. It was evident that people were being arrested who posed no threat to the public safety. Thereafter, the arrests subsided. Still, Lincoln himself reiterated the suspension on Sept. 24, and arrests without trial continued. Overall between 10,000 and 15,000 people were incarcerated without a prompt trial. On balance, their detention almost certainly did not enhance American security nor hasten the Union victory.

In the last 140 years, America has not faced a crisis anything like the Civil War, and the power to suspend habeas corpus has mostly gone unused. Although (as I’ll explain next week) the Supreme Court never definitively ruled Lincoln’s suspensions unconstitutional, his actions did come to be seen as a blemish on an otherwise heroic record of wartime leadership. That disrepute into which his behavior fell just may have helped deter his successors from using such measures themselves.

In the days after Sept. 11, George W. Bush was seen conspicuously toting around a new best-seller about the Civil War, as if to suggest he were reading up on the historical lessons of wartime leadership. It would be good if he brushed up not just on our greatest president’s heroics but also on his sad mistakes.